diff --git a/src/server/forms/register-as-a-unicorn-breeder.yaml b/src/server/forms/register-as-a-unicorn-breeder.yaml
index d8de940d6..2263aebfc 100644
--- a/src/server/forms/register-as-a-unicorn-breeder.yaml
+++ b/src/server/forms/register-as-a-unicorn-breeder.yaml
@@ -203,7 +203,7 @@ pages:
     path: '/how-many-members-of-staff-will-look-after-the-unicorns'
     section: susaYr
     next:
-      - path: '/summary'
+      - path: '/declaration'
     components:
       - name: zhJMaM
         options:
@@ -219,7 +219,7 @@ pages:
     controller: FileUploadPageController
     section: Regnsa
     next:
-      - path: '/declaration'
+      - path: '/how-many-unicorns-do-you-expect-to-breed-each-year'
     components:
       - name: dLzALM
         title: Documents
diff --git a/src/server/plugins/engine/components/EastingNorthingField.test.ts b/src/server/plugins/engine/components/EastingNorthingField.test.ts
index fa5e328a2..8cbebf244 100644
--- a/src/server/plugins/engine/components/EastingNorthingField.test.ts
+++ b/src/server/plugins/engine/components/EastingNorthingField.test.ts
@@ -556,14 +556,7 @@ describe('EastingNorthingField', () => {
                 easting: 12345.5,
                 northing: 1234567
               }),
-              // Two errors expected: decimal input triggers both integer validation
-              // and length validation ('12345.5' is 7 chars, max is 6)
               errors: [
-                expect.objectContaining({
-                  text: expect.stringMatching(
-                    /Easting for .* must be between 1 and 6 digits/
-                  )
-                }),
                 expect.objectContaining({
                   text: expect.stringMatching(
                     /Easting for .* must be between 1 and 6 digits/
@@ -582,14 +575,7 @@ describe('EastingNorthingField', () => {
                 easting: 12345,
                 northing: 1234567.5
               }),
-              // Two errors expected: decimal input triggers both integer validation
-              // and length validation ('1234567.5' is 9 chars, max is 7)
               errors: [
-                expect.objectContaining({
-                  text: expect.stringMatching(
-                    /Northing for .* must be between 1 and 7 digits/
-                  )
-                }),
                 expect.objectContaining({
                   text: expect.stringMatching(
                     /Northing for .* must be between 1 and 7 digits/
diff --git a/src/server/plugins/engine/components/EastingNorthingField.ts b/src/server/plugins/engine/components/EastingNorthingField.ts
index 16f38502e..2a48efc08 100644
--- a/src/server/plugins/engine/components/EastingNorthingField.ts
+++ b/src/server/plugins/engine/components/EastingNorthingField.ts
@@ -32,18 +32,6 @@ const DEFAULT_EASTING_MAX = 700000
 const DEFAULT_NORTHING_MIN = 0
 const DEFAULT_NORTHING_MAX = 1300000
 
-// Easting length constraints (integer values only, no decimals)
-// Min: 1 char for values like "0" or single digit values
-// Max: 6 chars for values up to 700000 (British National Grid easting limit)
-const EASTING_MIN_LENGTH = 1
-const EASTING_MAX_LENGTH = 6
-
-// Northing length constraints (integer values only, no decimals)
-// Min: 1 char for values like "0" or single digit values
-// Max: 7 chars for values up to 1300000 (British National Grid northing limit)
-const NORTHING_MIN_LENGTH = 1
-const NORTHING_MAX_LENGTH = 7
-
 export class EastingNorthingField extends FormComponent {
   declare options: EastingNorthingFieldComponent['options']
   declare formSchema: ObjectSchema<FormPayload>
@@ -73,9 +61,7 @@ export class EastingNorthingField extends FormComponent {
         'number.max': `{{#label}} for ${this.title} must be between ${eastingMin} and {{#limit}}`,
         'number.precision': `{{#label}} for ${this.title} must be between 1 and 6 digits`,
         'number.integer': `{{#label}} for ${this.title} must be between 1 and 6 digits`,
-        'number.unsafe': `{{#label}} for ${this.title} must be between 1 and 6 digits`,
-        'number.minLength': `{{#label}} for ${this.title} must be between 1 and 6 digits`,
-        'number.maxLength': `{{#label}} for ${this.title} must be between 1 and 6 digits`
+        'number.unsafe': `{{#label}} for ${this.title} must be between 1 and 6 digits`
       })
 
     const northingValidationMessages: LanguageMessages =
@@ -86,9 +72,7 @@ export class EastingNorthingField extends FormComponent {
         'number.max': `{{#label}} for ${this.title} must be between ${northingMin} and {{#limit}}`,
         'number.precision': `{{#label}} for ${this.title} must be between 1 and 7 digits`,
         'number.integer': `{{#label}} for ${this.title} must be between 1 and 7 digits`,
-        'number.unsafe': `{{#label}} for ${this.title} must be between 1 and 7 digits`,
-        'number.minLength': `{{#label}} for ${this.title} must be between 1 and 7 digits`,
-        'number.maxLength': `{{#label}} for ${this.title} must be between 1 and 7 digits`
+        'number.unsafe': `{{#label}} for ${this.title} must be between 1 and 7 digits`
       })
 
     this.collection = new ComponentCollection(
@@ -100,9 +84,7 @@ export class EastingNorthingField extends FormComponent {
           schema: {
             min: eastingMin,
             max: eastingMax,
-            precision: 0,
-            minLength: EASTING_MIN_LENGTH,
-            maxLength: EASTING_MAX_LENGTH
+            precision: 0
           },
           options: {
             required: isRequired,
@@ -118,9 +100,7 @@ export class EastingNorthingField extends FormComponent {
           schema: {
             min: northingMin,
             max: northingMax,
-            precision: 0,
-            minLength: NORTHING_MIN_LENGTH,
-            maxLength: NORTHING_MAX_LENGTH
+            precision: 0
           },
           options: {
             required: isRequired,
diff --git a/src/server/plugins/engine/components/LatLongField.test.ts b/src/server/plugins/engine/components/LatLongField.test.ts
index f8d9ce35f..6536506f6 100644
--- a/src/server/plugins/engine/components/LatLongField.test.ts
+++ b/src/server/plugins/engine/components/LatLongField.test.ts
@@ -578,15 +578,7 @@ describe('LatLongField', () => {
               value: getFormData({
                 latitude: 52,
                 longitude: -1
-              }),
-              errors: [
-                expect.objectContaining({
-                  text: 'Latitude must have at least 1 decimal place'
-                }),
-                expect.objectContaining({
-                  text: 'Longitude must have at least 1 decimal place'
-                })
-              ]
+              })
             }
           },
           {
@@ -619,7 +611,6 @@ describe('LatLongField', () => {
         description: 'Length and precision validation',
         component: createLatLongComponent(),
         assertions: [
-          // Latitude too short
           {
             input: getFormData({
               latitude: '52',
@@ -629,12 +620,7 @@ describe('LatLongField', () => {
               value: getFormData({
                 latitude: 52,
                 longitude: -1.5
-              }),
-              errors: [
-                expect.objectContaining({
-                  text: 'Latitude must have at least 1 decimal place'
-                })
-              ]
+              })
             }
           },
           // Latitude too long
@@ -655,7 +641,6 @@ describe('LatLongField', () => {
               ]
             }
           },
-          // Longitude too short
           {
             input: getFormData({
               latitude: '52.1',
@@ -665,12 +650,7 @@ describe('LatLongField', () => {
               value: getFormData({
                 latitude: 52.1,
                 longitude: -1
-              }),
-              errors: [
-                expect.objectContaining({
-                  text: 'Longitude must have at least 1 decimal place'
-                })
-              ]
+              })
             }
           },
           // Longitude too long
diff --git a/src/server/plugins/engine/components/LatLongField.ts b/src/server/plugins/engine/components/LatLongField.ts
index 0ccb9ef88..f90beb541 100644
--- a/src/server/plugins/engine/components/LatLongField.ts
+++ b/src/server/plugins/engine/components/LatLongField.ts
@@ -26,19 +26,6 @@ import { convertToLanguageMessages } from '~/src/server/utils/type-utils.js'
 // Precision constants
 // UK latitude/longitude requires high precision for accurate location (within ~11mm)
 const DECIMAL_PRECISION = 7 // 7 decimal places
-const MIN_DECIMAL_PLACES = 1 // At least 1 decimal place required
-
-// Latitude length constraints
-// Min: 3 chars for values like "52.1" (2 digits + decimal + 1 decimal place)
-// Max: 10 chars for values like "59.1234567" (2 digits + decimal + 7 decimal places)
-const LATITUDE_MIN_LENGTH = 3
-const LATITUDE_MAX_LENGTH = 10
-
-// Longitude length constraints
-// Min: 2 chars for values like "-1" or single digit with decimal (needs min decimal places)
-// Max: 10 chars for values like "-1.1234567" (minus + 1 digit + decimal + 7 decimal places)
-const LONGITUDE_MIN_LENGTH = 2
-const LONGITUDE_MAX_LENGTH = 10
 
 export class LatLongField extends FormComponent {
   declare options: LatLongFieldComponent['options']
@@ -68,8 +55,6 @@ export class LatLongField extends FormComponent {
         'number.base': messageTemplate.objectMissing,
         'number.precision':
           '{{#label}} must have no more than 7 decimal places',
-        'number.minPrecision':
-          '{{#label}} must have at least {{#minPrecision}} decimal place',
         'number.unsafe': '{{#label}} must be a valid number'
       })
 
@@ -77,18 +62,14 @@ export class LatLongField extends FormComponent {
       ...customValidationMessages,
       'number.base': `Enter a valid latitude for ${this.title} like 51.519450`,
       'number.min': `Latitude for ${this.title} must be between ${latitudeMin} and ${latitudeMax}`,
-      'number.max': `Latitude for ${this.title} must be between ${latitudeMin} and ${latitudeMax}`,
-      'number.minLength': `Latitude for ${this.title} must be between 3 and 10 characters`,
-      'number.maxLength': `Latitude for ${this.title} must be between 3 and 10 characters`
+      'number.max': `Latitude for ${this.title} must be between ${latitudeMin} and ${latitudeMax}`
     })
 
     const longitudeMessages: LanguageMessages = convertToLanguageMessages({
       ...customValidationMessages,
       'number.base': `Enter a valid longitude for ${this.title} like -0.127758`,
       'number.min': `Longitude for ${this.title} must be between ${longitudeMin} and ${longitudeMax}`,
-      'number.max': `Longitude for ${this.title} must be between ${longitudeMin} and ${longitudeMax}`,
-      'number.minLength': `Longitude for ${this.title} must be between 2 and 10 characters`,
-      'number.maxLength': `Longitude for ${this.title} must be between 2 and 10 characters`
+      'number.max': `Longitude for ${this.title} must be between ${longitudeMin} and ${longitudeMax}`
     })
 
     this.collection = new ComponentCollection(
@@ -100,10 +81,7 @@ export class LatLongField extends FormComponent {
           schema: {
             min: latitudeMin,
             max: latitudeMax,
-            precision: DECIMAL_PRECISION,
-            minPrecision: MIN_DECIMAL_PLACES,
-            minLength: LATITUDE_MIN_LENGTH,
-            maxLength: LATITUDE_MAX_LENGTH
+            precision: DECIMAL_PRECISION
           },
           options: {
             required: isRequired,
@@ -120,10 +98,7 @@ export class LatLongField extends FormComponent {
           schema: {
             min: longitudeMin,
             max: longitudeMax,
-            precision: DECIMAL_PRECISION,
-            minPrecision: MIN_DECIMAL_PLACES,
-            minLength: LONGITUDE_MIN_LENGTH,
-            maxLength: LONGITUDE_MAX_LENGTH
+            precision: DECIMAL_PRECISION
           },
           options: {
             required: isRequired,
diff --git a/src/server/plugins/engine/components/LocationFieldBase.ts b/src/server/plugins/engine/components/LocationFieldBase.ts
index e91ca7eed..824d0f0bf 100644
--- a/src/server/plugins/engine/components/LocationFieldBase.ts
+++ b/src/server/plugins/engine/components/LocationFieldBase.ts
@@ -28,11 +28,6 @@ interface LocationFieldOptions {
 interface ValidationConfig {
   pattern: RegExp
   patternErrorMessage: string
-  customValidation?: (
-    value: string,
-    helpers: joi.CustomHelpers
-  ) => string | joi.ErrorReport
-  additionalMessages?: LanguageMessages
 }
 
 /**
@@ -71,14 +66,9 @@ export abstract class LocationFieldBase extends FormComponent {
       .required()
       .pattern(config.pattern)
       .messages({
-        'string.pattern.base': config.patternErrorMessage,
-        ...config.additionalMessages
+        'string.pattern.base': config.patternErrorMessage
       })
 
-    if (config.customValidation) {
-      formSchema = formSchema.custom(config.customValidation)
-    }
-
     if (locationOptions.required === false) {
       formSchema = formSchema.allow('')
     }
@@ -91,10 +81,6 @@ export abstract class LocationFieldBase extends FormComponent {
         'string.pattern.base'
       ]
 
-      if (config.additionalMessages) {
-        messageKeys.push(...Object.keys(config.additionalMessages))
-      }
-
       const messages = messageKeys.reduce<LanguageMessages>((acc, key) => {
         acc[key] = message
         return acc
diff --git a/src/server/plugins/engine/components/NationalGridFieldNumberField.test.ts b/src/server/plugins/engine/components/NationalGridFieldNumberField.test.ts
index 7b505c406..2f52ca83d 100644
--- a/src/server/plugins/engine/components/NationalGridFieldNumberField.test.ts
+++ b/src/server/plugins/engine/components/NationalGridFieldNumberField.test.ts
@@ -99,13 +99,27 @@ describe('NationalGridFieldNumberField', () => {
       })
 
       it('accepts valid values', () => {
-        const result1 = collection.validate(getFormData('NG12345678'))
-        const result2 = collection.validate(getFormData('ng12345678'))
-        const result3 = collection.validate(getFormData('AB98765432'))
+        // Test 8-digit parcel ID format (2x4)
+        const result1 = collection.validate(getFormData('TQ12345678'))
+        const result2 = collection.validate(getFormData('TQ 1234 5678'))
+
+        // Test 10-digit OS grid reference format (2x5)
+        const result3 = collection.validate(getFormData('SU1234567890'))
+        const result4 = collection.validate(getFormData('SU 12345 67890'))
+
+        expect(result1.errors).toBeUndefined()
+        expect(result2.errors).toBeUndefined()
+        expect(result3.errors).toBeUndefined()
+        expect(result4.errors).toBeUndefined()
+
+        // Test case-insensitive
+        const result5 = collection.validate(getFormData('nt12345678'))
 
         expect(result1.errors).toBeUndefined()
         expect(result2.errors).toBeUndefined()
         expect(result3.errors).toBeUndefined()
+        expect(result4.errors).toBeUndefined()
+        expect(result5.errors).toBeUndefined()
       })
 
       it('formats values with spaces per GDS guidance', () => {
@@ -114,8 +128,8 @@ describe('NationalGridFieldNumberField', () => {
         const result3 = collection.validate(getFormData('NG12345,678'))
 
         expect(result1.value.myComponent).toBe('NG 1234 5678')
-        expect(result2.value.myComponent).toBe('NG 1234 5678')
-        expect(result3.value.myComponent).toBe('NG 1234 5678')
+        expect(result2.value.myComponent).toBe('NG12345678')
+        expect(result3.value.myComponent).toBe('NG12345,678')
       })
 
       it('adds errors for empty value', () => {
@@ -258,15 +272,15 @@ describe('NationalGridFieldNumberField', () => {
         assertions: [
           {
             input: getFormData('  NG12345678'),
-            output: { value: getFormData('NG 1234 5678') }
+            output: { value: getFormData('NG12345678') }
           },
           {
             input: getFormData('NG12345678  '),
-            output: { value: getFormData('NG 1234 5678') }
+            output: { value: getFormData('NG12345678') }
           },
           {
             input: getFormData('  NG12345678 \n\n'),
-            output: { value: getFormData('NG 1234 5678') }
+            output: { value: getFormData('NG12345678') }
           }
         ]
       },
diff --git a/src/server/plugins/engine/components/NationalGridFieldNumberField.ts b/src/server/plugins/engine/components/NationalGridFieldNumberField.ts
index a1efe74c9..19400d7e4 100644
--- a/src/server/plugins/engine/components/NationalGridFieldNumberField.ts
+++ b/src/server/plugins/engine/components/NationalGridFieldNumberField.ts
@@ -1,5 +1,4 @@
 import { type NationalGridFieldNumberFieldComponent } from '@defra/forms-model'
-import type joi from 'joi'
 
 import { LocationFieldBase } from '~/src/server/plugins/engine/components/LocationFieldBase.js'
 
@@ -7,26 +6,16 @@ export class NationalGridFieldNumberField extends LocationFieldBase {
   declare options: NationalGridFieldNumberFieldComponent['options']
 
   protected getValidationConfig() {
-    return {
-      // Pattern allows spaces and commas in the input since custom validation will clean them
-      pattern: /^[A-Z]{2}[\d\s,]*$/i,
-      patternErrorMessage: `Enter a valid National Grid field number for ${this.title} like NG 1234 5678`,
-      customValidation: (value: string, helpers: joi.CustomHelpers) => {
-        // Strip spaces and commas for validation
-        const cleanValue = value.replace(/[\s,]/g, '')
-
-        // Check if it matches the exact pattern after cleaning
-        if (!/^[A-Z]{2}\d{8}$/i.test(cleanValue)) {
-          return helpers.error('string.pattern.base')
-        }
-
-        // Format with spaces per GDS guidance: NG 1234 5678
-        const letters = cleanValue.substring(0, 2)
-        const numbers = cleanValue.substring(2)
-        const formattedValue = `${letters} ${numbers.substring(0, 4)} ${numbers.substring(4)}`
+    // Regex for OS grid references and parcel IDs
+    // Validates specific valid OS grid letter combinations with:
+    // - 2 letters & 8 digits in 2 blocks of 4 (parcel ID) e.g., ST 6789 6789
+    // - 2 letters & 10 digits in 2 blocks of 5 (OS grid reference) e.g., SO 12345 12345
+    const pattern =
+      /^((([sS]|[nN])[a-hA-Hj-zJ-Z])|(([tT]|[oO])[abfglmqrvwABFGLMQRVW])|([hH][l-zL-Z])|([jJ][lmqrvwLMQRVW]))\s?(([0-9]{4})\s?([0-9]{4})|([0-9]{5})\s?([0-9]{5}))$/
 
-        return formattedValue
-      }
+    return {
+      pattern,
+      patternErrorMessage: `Enter a valid National Grid field number for ${this.title} like NG 1234 5678`
     }
   }
 
diff --git a/src/server/plugins/engine/components/NumberField.test.ts b/src/server/plugins/engine/components/NumberField.test.ts
index 9bc995e90..28b266df0 100644
--- a/src/server/plugins/engine/components/NumberField.test.ts
+++ b/src/server/plugins/engine/components/NumberField.test.ts
@@ -1,10 +1,7 @@
 import { ComponentType, type NumberFieldComponent } from '@defra/forms-model'
 
 import { ComponentCollection } from '~/src/server/plugins/engine/components/ComponentCollection.js'
-import {
-  NumberField,
-  validateMinimumPrecision
-} from '~/src/server/plugins/engine/components/NumberField.js'
+import { NumberField } from '~/src/server/plugins/engine/components/NumberField.js'
 import {
   getAnswer,
   type Field
@@ -22,31 +19,6 @@ describe('NumberField', () => {
     })
   })
 
-  describe('Helper Functions', () => {
-    describe('validateMinimumPrecision', () => {
-      it('returns false for integers', () => {
-        expect(validateMinimumPrecision(52, 1)).toBe(false)
-        expect(validateMinimumPrecision(100, 2)).toBe(false)
-      })
-
-      it('validates minimum precision correctly', () => {
-        expect(validateMinimumPrecision(52.1, 1)).toBe(true)
-        expect(validateMinimumPrecision(52.12, 2)).toBe(true)
-        expect(validateMinimumPrecision(52.123, 3)).toBe(true)
-      })
-
-      it('returns false when precision is insufficient', () => {
-        expect(validateMinimumPrecision(52.1, 2)).toBe(false)
-        expect(validateMinimumPrecision(52.12, 3)).toBe(false)
-      })
-
-      it('handles exact precision requirement', () => {
-        expect(validateMinimumPrecision(52.12345, 5)).toBe(true)
-        expect(validateMinimumPrecision(52.1234, 5)).toBe(false)
-      })
-    })
-  })
-
   describe('Defaults', () => {
     let def: NumberFieldComponent
     let collection: ComponentCollection
@@ -532,184 +504,17 @@ describe('NumberField', () => {
         ]
       },
       {
-        description: 'Schema minPrecision (minimum 1 decimal place)',
-        component: createPrecisionTestComponent(1),
-        assertions: [
-          {
-            input: getFormData('52'),
-            output: {
-              value: getFormData(52),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must have at least 1 decimal place'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('52.0'),
-            output: {
-              value: getFormData(52),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must have at least 1 decimal place'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('52.1'),
-            output: { value: getFormData(52.1) }
-          },
-          {
-            input: getFormData('52.123456'),
-            output: { value: getFormData(52.123456) }
-          }
-        ]
-      },
-      {
-        description: 'Schema minPrecision (minimum 2 decimal places)',
-        component: createPrecisionTestComponent(2),
-        assertions: [
-          {
-            input: getFormData('52.1'),
-            output: {
-              value: getFormData(52.1),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must have at least 2 decimal places'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('52.12'),
-            output: { value: getFormData(52.12) }
-          },
-          {
-            input: getFormData('52.1234567'),
-            output: { value: getFormData(52.1234567) }
-          }
-        ]
-      },
-      {
-        description: 'Schema minLength (minimum 3 characters)',
-        component: createLengthTestComponent(3, undefined),
-        assertions: [
-          {
-            input: getFormData('12'),
-            output: {
-              value: getFormData(12),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must be at least 3 characters'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('123'),
-            output: { value: getFormData(123) }
-          },
-          {
-            input: getFormData('1234'),
-            output: { value: getFormData(1234) }
-          }
-        ]
-      },
-      {
-        description: 'Schema maxLength (maximum 5 characters)',
-        component: createLengthTestComponent(undefined, 5),
-        assertions: [
-          {
-            input: getFormData('123456'),
-            output: {
-              value: getFormData(123456),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must be no more than 5 characters'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('12345'),
-            output: { value: getFormData(12345) }
-          },
-          {
-            input: getFormData('123'),
-            output: { value: getFormData(123) }
-          }
-        ]
-      },
-      {
-        description:
-          'Schema minLength and maxLength (3-8 characters, like latitude)',
+        description: 'Schema min and max',
         component: {
-          title: 'Latitude field',
-          shortDescription: 'Latitude',
+          title: 'Example number field',
           name: 'myComponent',
           type: ComponentType.NumberField,
-          options: {
-            customValidationMessages: {
-              'number.minPrecision':
-                '{{#label}} must have at least {{#minPrecision}} decimal place',
-              'number.minLength':
-                '{{#label}} must be between 3 and 10 characters',
-              'number.maxLength':
-                '{{#label}} must be between 3 and 10 characters'
-            }
-          },
-          schema: {
-            min: 49,
-            max: 60,
-            precision: 7,
-            minPrecision: 1,
-            minLength: 3,
-            maxLength: 10
-          }
-        } as NumberFieldComponent,
-        assertions: [
-          {
-            input: getFormData('52'),
-            output: {
-              value: getFormData(52),
-              errors: [
-                expect.objectContaining({
-                  text: 'Latitude must have at least 1 decimal place'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('52.12345678'),
-            output: {
-              value: getFormData(52.12345678),
-              errors: [
-                expect.objectContaining({
-                  text: 'Latitude must have 7 or fewer decimal places'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('52.1'),
-            output: { value: getFormData(52.1) }
-          },
-          {
-            input: getFormData('52.1234'),
-            output: { value: getFormData(52.1234) }
-          }
-        ]
-      },
-      {
-        description: 'Schema min and max',
-        component: createNumberComponent({
+          options: {},
           schema: {
             min: 5,
             max: 8
           }
-        }),
+        } satisfies NumberFieldComponent,
         assertions: [
           {
             input: getFormData('4'),
@@ -737,7 +542,10 @@ describe('NumberField', () => {
       },
       {
         description: 'Custom validation message',
-        component: createNumberComponent({
+        component: {
+          title: 'Example number field',
+          name: 'myComponent',
+          type: ComponentType.NumberField,
           options: {
             customValidationMessage: 'This is a custom error',
             customValidationMessages: {
@@ -746,8 +554,9 @@ describe('NumberField', () => {
               'number.min': 'This is not used',
               'number.max': 'This is not used'
             }
-          }
-        }),
+          },
+          schema: {}
+        } satisfies NumberFieldComponent,
         assertions: [
           {
             input: getFormData(''),
@@ -877,86 +686,6 @@ describe('NumberField', () => {
           }
         ]
       },
-      {
-        description: 'Custom validation message overrides length validation',
-        component: {
-          title: 'Example number field',
-          name: 'myComponent',
-          type: ComponentType.NumberField,
-          options: {
-            customValidationMessage: 'This is a custom length error'
-          },
-          schema: {
-            minLength: 3,
-            maxLength: 5
-          }
-        } satisfies NumberFieldComponent,
-        assertions: [
-          {
-            input: getFormData('12'),
-            output: {
-              value: getFormData(12),
-              errors: [
-                expect.objectContaining({
-                  text: 'This is a custom length error'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('123456'),
-            output: {
-              value: getFormData(123456),
-              errors: [
-                expect.objectContaining({
-                  text: 'This is a custom length error'
-                })
-              ]
-            }
-          }
-        ]
-      },
-      {
-        description: 'Default length validation messages (no custom messages)',
-        component: {
-          title: 'Example number field',
-          name: 'myComponent',
-          type: ComponentType.NumberField,
-          options: {},
-          schema: {
-            minLength: 3,
-            maxLength: 5
-          }
-        } satisfies NumberFieldComponent,
-        assertions: [
-          {
-            input: getFormData('12'),
-            output: {
-              value: getFormData(12),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must be at least 3 characters'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('123456'),
-            output: {
-              value: getFormData(123456),
-              errors: [
-                expect.objectContaining({
-                  text: 'Example number field must be no more than 5 characters'
-                })
-              ]
-            }
-          },
-          {
-            input: getFormData('1234'),
-            output: { value: getFormData(1234) }
-          }
-        ]
-      },
       {
         description: 'Optional field',
         component: {
@@ -991,202 +720,4 @@ describe('NumberField', () => {
       )
     })
   })
-
-  describe('Edge cases', () => {
-    let collection: ComponentCollection
-
-    beforeEach(() => {
-      const def = createNumberComponent({
-        schema: {
-          min: -100,
-          max: 100,
-          precision: 2
-        }
-      })
-      collection = new ComponentCollection([def], { model })
-    })
-
-    it('handles negative numbers correctly', () => {
-      const result = collection.validate(getFormData('-50.5'))
-      expect(result).toEqual({
-        value: getFormData(-50.5)
-      })
-    })
-
-    it('handles zero correctly', () => {
-      const result = collection.validate(getFormData('0'))
-      expect(result).toEqual({
-        value: getFormData(0)
-      })
-    })
-
-    it('handles zero with decimal correctly', () => {
-      const result = collection.validate(getFormData('0.0'))
-      expect(result).toEqual({
-        value: getFormData(0)
-      })
-    })
-
-    it('handles negative zero correctly', () => {
-      const result = collection.validate(getFormData('-0'))
-      expect(result).toEqual({
-        value: getFormData(0)
-      })
-    })
-
-    it('handles scientific notation (parsed as number, may fail range)', () => {
-      // JavaScript parses '1e10' as 10000000000, which exceeds max of 100
-      const result = collection.validate(getFormData('1e10'))
-      expect(result).toEqual({
-        value: getFormData(10000000000),
-        errors: [
-          expect.objectContaining({
-            text: 'Example number field must be 100 or lower'
-          })
-        ]
-      })
-    })
-
-    it('handles scientific notation with negative exponent (parsed as number)', () => {
-      // JavaScript parses '1e-5' as 0.00001, which fails precision check (5 decimal places > 2)
-      const result = collection.validate(getFormData('1e-5'))
-      expect(result.value).toEqual(getFormData(0.00001))
-      expect(result.errors).toBeDefined()
-      expect(result.errors?.[0]).toMatchObject({
-        text: 'Example number field must have 2 or fewer decimal places'
-      })
-    })
-
-    it('handles large negative numbers', () => {
-      const result = collection.validate(getFormData('-99.99'))
-      expect(result).toEqual({
-        value: getFormData(-99.99)
-      })
-    })
-
-    it('handles numbers at boundary limits', () => {
-      const maxResult = collection.validate(getFormData('100'))
-      expect(maxResult).toEqual({
-        value: getFormData(100)
-      })
-
-      const minResult = collection.validate(getFormData('-100'))
-      expect(minResult).toEqual({
-        value: getFormData(-100)
-      })
-    })
-
-    describe('with length constraints', () => {
-      beforeEach(() => {
-        const def = createNumberComponent({
-          schema: {
-            min: -9,
-            max: 9,
-            precision: 7,
-            minPrecision: 1,
-            minLength: 2,
-            maxLength: 10
-          },
-          options: {
-            customValidationMessages: {
-              'number.minPrecision':
-                'Example number field must have at least {{minPrecision}} decimal place',
-              'number.precision':
-                'Example number field must have no more than {{limit}} decimal places',
-              'number.minLength':
-                'Example number field must be at least {{minLength}} characters',
-              'number.maxLength':
-                'Example number field must be no more than {{maxLength}} characters'
-            }
-          }
-        })
-        collection = new ComponentCollection([def], { model })
-      })
-
-      it('validates negative numbers with decimals', () => {
-        const result = collection.validate(getFormData('-5.1234567'))
-        expect(result).toEqual({
-          value: getFormData(-5.1234567)
-        })
-      })
-
-      it('rejects negative numbers that are too short', () => {
-        const result = collection.validate(getFormData('-5'))
-        expect(result.value).toEqual(getFormData(-5))
-        expect(result.errors).toBeDefined()
-        expect(result.errors?.[0].text).toContain('decimal place')
-      })
-
-      it('rejects numbers with too many characters', () => {
-        const result = collection.validate(getFormData('-5.12345678'))
-        expect(result.value).toEqual(getFormData(-5.12345678))
-        expect(result.errors).toBeDefined()
-        expect(result.errors?.[0].text).toContain('decimal places')
-      })
-    })
-  })
 })
-
-/**
- * Factory function to create a default NumberField component with optional overrides
- */
-function createNumberComponent(
-  overrides: Partial<NumberFieldComponent> = {}
-): NumberFieldComponent {
-  const base = {
-    title: 'Example number field',
-    name: 'myComponent',
-    type: ComponentType.NumberField,
-    options: {},
-    schema: {}
-  } satisfies NumberFieldComponent
-
-  // Deep merge for nested objects like options and schema
-  return {
-    ...base,
-    ...overrides,
-    options: { ...base.options, ...(overrides.options ?? {}) },
-    schema: { ...base.schema, ...(overrides.schema ?? {}) }
-  } satisfies NumberFieldComponent
-}
-
-/**
- * Helper for precision validation tests
- */
-function createPrecisionTestComponent(
-  minPrecision: number,
-  precision = 7
-): NumberFieldComponent {
-  const pluralSuffix = minPrecision > 1 ? 's' : ''
-  return createNumberComponent({
-    options: {
-      customValidationMessages: {
-        'number.minPrecision': `{{#label}} must have at least {{#minPrecision}} decimal place${pluralSuffix}`
-      }
-    },
-    schema: { precision, minPrecision }
-  })
-}
-
-/**
- * Helper for length validation tests
- */
-function createLengthTestComponent(
-  minLength?: number,
-  maxLength?: number
-): NumberFieldComponent {
-  const messages: Record<string, string> = {}
-  if (minLength) {
-    messages['number.minLength'] =
-      '{{#label}} must be at least {{#minLength}} characters'
-  }
-  if (maxLength) {
-    messages['number.maxLength'] =
-      '{{#label}} must be no more than {{#maxLength}} characters'
-  }
-
-  return createNumberComponent({
-    options: { customValidationMessages: messages },
-    schema: { minLength, maxLength }
-  })
-}
diff --git a/src/server/plugins/engine/components/NumberField.ts b/src/server/plugins/engine/components/NumberField.ts
index 524d65921..787716255 100644
--- a/src/server/plugins/engine/components/NumberField.ts
+++ b/src/server/plugins/engine/components/NumberField.ts
@@ -15,26 +15,6 @@ import {
   type FormSubmissionState
 } from '~/src/server/plugins/engine/types.js'
 
-/**
- * Checks if precision requires integer-only validation
- * @param precision - The precision value from schema
- * @returns true if integers only (precision <= 0 or undefined)
- */
-function isIntegerOnlyPrecision(
-  precision: number | undefined
-): precision is number {
-  return typeof precision === 'number' && precision <= 0
-}
-
-/**
- * Checks if field should use numeric inputmode
- * @param precision - The precision value from schema
- * @returns true if numeric inputmode should be used
- */
-function shouldUseNumericInputMode(precision: number | undefined): boolean {
-  return typeof precision === 'undefined' || precision <= 0
-}
-
 export class NumberField extends FormComponent {
   declare options: NumberFieldComponent['options']
   declare schema: NumberFieldComponent['schema']
@@ -75,7 +55,7 @@ export class NumberField extends FormComponent {
       formSchema = formSchema.max(schema.max)
     }
 
-    if (isIntegerOnlyPrecision(schema.precision)) {
+    if (typeof schema.precision === 'number' && schema.precision <= 0) {
       formSchema = formSchema.integer()
     }
 
@@ -88,9 +68,7 @@ export class NumberField extends FormComponent {
         'number.precision': message,
         'number.integer': message,
         'number.min': message,
-        'number.max': message,
-        'number.minLength': message,
-        'number.maxLength': message
+        'number.max': message
       })
     } else if (options.customValidationMessages) {
       formSchema = formSchema.messages(options.customValidationMessages)
@@ -117,7 +95,7 @@ export class NumberField extends FormComponent {
     const viewModel = super.getViewModel(payload, errors)
     let { attributes, prefix, suffix, value } = viewModel
 
-    if (shouldUseNumericInputMode(schema.precision)) {
+    if (typeof schema.precision === 'undefined' || schema.precision <= 0) {
       // If precision isn't provided or provided and
       // less than or equal to 0, use numeric inputmode
       attributes.inputmode = 'numeric'
@@ -183,128 +161,29 @@ export class NumberField extends FormComponent {
   }
 }
 
-/**
- * Validates minimum decimal precision
- * @param value - The numeric value to validate
- * @param minPrecision - Minimum required decimal places
- * @returns true if valid, false if invalid
- */
-export function validateMinimumPrecision(
-  value: number,
-  minPrecision: number
-): boolean {
-  if (Number.isInteger(value)) {
-    return false
-  }
-
-  const valueStr = String(value)
-  const decimalIndex = valueStr.indexOf('.')
-
-  if (decimalIndex !== -1) {
-    const decimalPlaces = valueStr.length - decimalIndex - 1
-    return decimalPlaces >= minPrecision
-  }
-
-  return false
-}
-
-function validateStringLengthWithJoi(
-  value: number,
-  minLength: number | undefined,
-  maxLength: number | undefined,
-  helpers: joi.CustomHelpers,
-  custom: string | undefined,
-  customMessages: Record<string, string> | undefined
-) {
-  const hasMinLength = typeof minLength === 'number'
-  const hasMaxLength = typeof maxLength === 'number'
-
-  if (!hasMinLength && !hasMaxLength) {
-    return null
-  }
-
-  const valueStr = String(value)
-  let stringValidator = joi.string()
-
-  if (hasMinLength) {
-    stringValidator = stringValidator.min(minLength)
-  }
-  if (hasMaxLength) {
-    stringValidator = stringValidator.max(maxLength)
-  }
-
-  const { error } = stringValidator.validate(valueStr)
-  if (!error) {
-    return null
-  }
-
-  const isMinError = error.details[0]?.type === 'string.min'
-  const messageKey = isMinError ? 'number.minLength' : 'number.maxLength'
-  const context = isMinError ? { minLength } : { maxLength }
-
-  if (custom) {
-    return helpers.message({ custom }, context)
-  }
-
-  if (customMessages?.[messageKey]) {
-    return helpers.message({ custom: customMessages[messageKey] }, context)
-  }
-
-  const defaultMessage = isMinError
-    ? `{{#label}} must be at least ${minLength} characters`
-    : `{{#label}} must be no more than ${maxLength} characters`
-  return helpers.message({ custom: defaultMessage })
-}
-
 export function getValidatorPrecision(component: NumberField) {
   const validator: CustomValidator = (value: number, helpers) => {
     const { options, schema } = component
-    const { customValidationMessage: custom } = options
-    const {
-      precision: limit,
-      minPrecision,
-      minLength,
-      maxLength
-    } = schema as {
-      precision?: number
-      minPrecision?: number
-      minLength?: number
-      maxLength?: number
-    }
 
-    // Validate maximum precision if limit is set
-    // Note: We need a separate schema with convert:false to prevent rounding
-    if (limit && limit > 0) {
-      const precisionSchema = joi
-        .number()
-        .precision(limit)
-        .prefs({ convert: false })
-
-      const { error } = precisionSchema.validate(value)
-      if (error) {
-        return custom
-          ? helpers.message({ custom }, { limit })
-          : helpers.error('number.precision', { limit })
-      }
+    const { customValidationMessage: custom } = options
+    const { precision: limit } = schema
 
-      if (typeof minPrecision === 'number' && minPrecision > 0) {
-        if (!validateMinimumPrecision(value, minPrecision)) {
-          return helpers.error('number.minPrecision', { minPrecision })
-        }
-      }
+    if (!limit || limit <= 0) {
+      return value
     }
 
-    const lengthError = validateStringLengthWithJoi(
-      value,
-      minLength,
-      maxLength,
-      helpers,
-      custom,
-      options.customValidationMessages as Record<string, string> | undefined
-    )
-    if (lengthError) return lengthError
-
-    return value
+    const validationSchema = joi
+      .number()
+      .precision(limit)
+      .prefs({ convert: false })
+
+    try {
+      return joi.attempt(value, validationSchema)
+    } catch {
+      return custom
+        ? helpers.message({ custom }, { limit })
+        : helpers.error('number.precision', { limit })
+    }
   }
 
   return validator
diff --git a/src/server/plugins/engine/components/OsGridRefField.test.ts b/src/server/plugins/engine/components/OsGridRefField.test.ts
index 6f8303cae..3af774b35 100644
--- a/src/server/plugins/engine/components/OsGridRefField.test.ts
+++ b/src/server/plugins/engine/components/OsGridRefField.test.ts
@@ -100,46 +100,24 @@ describe('OsGridRefField', () => {
         const result1 = collection.validate(getFormData('SD865005'))
         const result2 = collection.validate(getFormData('SD 865 005'))
 
-        // Test 8-digit parcel ID format (2x4)
-        const result3 = collection.validate(getFormData('TQ12345678'))
-        const result4 = collection.validate(getFormData('TQ 1234 5678'))
-
-        // Test 10-digit OS grid reference format (2x5)
-        const result5 = collection.validate(getFormData('SU1234567890'))
-        const result6 = collection.validate(getFormData('SU 12345 67890'))
-
         // Test case-insensitive
-        const result7 = collection.validate(getFormData('nt12345678'))
-
-        // Test various valid OS grid formats
-        const result8 = collection.validate(getFormData('SN 1232 1223')) // parcel ID format
-        const result9 = collection.validate(getFormData('SN 12324 12234')) // OS grid ref format
-        const result10 = collection.validate(getFormData('ST 6789 6789')) // parcel ID with different letters
-        const result11 = collection.validate(getFormData('SO 12345 12345')) // OS grid ref with different letters
+        const result3 = collection.validate(getFormData('nt123456'))
 
         expect(result1.errors).toBeUndefined()
         expect(result2.errors).toBeUndefined()
         expect(result3.errors).toBeUndefined()
-        expect(result4.errors).toBeUndefined()
-        expect(result5.errors).toBeUndefined()
-        expect(result6.errors).toBeUndefined()
-        expect(result7.errors).toBeUndefined()
-        expect(result8.errors).toBeUndefined()
-        expect(result9.errors).toBeUndefined()
-        expect(result10.errors).toBeUndefined()
-        expect(result11.errors).toBeUndefined()
       })
 
-      it('formats values with spaces per GDS guidance', () => {
+      it('retains values with spaces per GDS guidance', () => {
         const result1 = collection.validate(getFormData('SD865005'))
         const result2 = collection.validate(getFormData('TQ 1234 5678'))
         const result3 = collection.validate(getFormData('SU1234567890'))
         const result4 = collection.validate(getFormData('TQ12345678'))
 
-        expect(result1.value.myComponent).toBe('SD 865 005')
+        expect(result1.value.myComponent).toBe('SD865005')
         expect(result2.value.myComponent).toBe('TQ 1234 5678')
-        expect(result3.value.myComponent).toBe('SU 12345 67890')
-        expect(result4.value.myComponent).toBe('TQ 1234 5678')
+        expect(result3.value.myComponent).toBe('SU1234567890')
+        expect(result4.value.myComponent).toBe('TQ12345678')
       })
 
       it('adds errors for empty value', () => {
@@ -289,16 +267,16 @@ describe('OsGridRefField', () => {
         },
         assertions: [
           {
-            input: getFormData('  TQ12345678'),
-            output: { value: getFormData('TQ 1234 5678') }
+            input: getFormData('  TQ123456'),
+            output: { value: getFormData('TQ123456') }
           },
           {
-            input: getFormData('TQ12345678  '),
-            output: { value: getFormData('TQ 1234 5678') }
+            input: getFormData('TQ123456  '),
+            output: { value: getFormData('TQ123456') }
           },
           {
-            input: getFormData('  TQ12345678 \n\n'),
-            output: { value: getFormData('TQ 1234 5678') }
+            input: getFormData('  TQ123456 \n\n'),
+            output: { value: getFormData('TQ123456') }
           }
         ]
       },
diff --git a/src/server/plugins/engine/components/OsGridRefField.ts b/src/server/plugins/engine/components/OsGridRefField.ts
index e9d8ce598..5a27e8147 100644
--- a/src/server/plugins/engine/components/OsGridRefField.ts
+++ b/src/server/plugins/engine/components/OsGridRefField.ts
@@ -1,5 +1,4 @@
 import { type OsGridRefFieldComponent } from '@defra/forms-model'
-import type joi from 'joi'
 
 import { LocationFieldBase } from '~/src/server/plugins/engine/components/LocationFieldBase.js'
 
@@ -9,45 +8,13 @@ export class OsGridRefField extends LocationFieldBase {
   protected getValidationConfig() {
     // Regex for OS grid references and parcel IDs
     // Validates specific valid OS grid letter combinations with:
-    // - 6 digits (e.g., SD865005 or SD 865 005)
-    // - 8 digits in 2 blocks of 4 (parcel ID) e.g., ST 6789 6789
-    // - 10 digits in 2 blocks of 5 (OS grid reference) e.g., SO 12345 12345
-    const osGridPattern =
-      /^(?:[sn][a-hj-z]|[to][abfglmqrvw]|h[l-z]|j[lmqrvw])\s?(?:\d{3}\s?\d{3}|\d{4}\s?\d{4}|\d{5}\s?\d{5})$/i
-
-    // More permissive pattern for initial validation (allows spaces to be cleaned)
-    const initialPattern = /^[A-Za-z]{2}[\d\s]*$/
+    // - 2 letters & 6 digits (e.g., SD865005 or SD 865 005)
+    const pattern =
+      /^((([sS]|[nN])[a-hA-Hj-zJ-Z])|(([tT]|[oO])[abfglmqrvwABFGLMQRVW])|([hH][l-zL-Z])|([jJ][lmqrvwLMQRVW]))\s?(([0-9]{3})\s?([0-9]{3}))$/
 
     return {
-      pattern: initialPattern,
-      patternErrorMessage: `Enter a valid OS grid reference for ${this.title} like TQ123456`,
-      customValidation: (value: string, helpers: joi.CustomHelpers) => {
-        // Strip spaces from the input for processing
-        const cleanValue = value.replace(/\s/g, '')
-        const letters = cleanValue.substring(0, 2)
-        const numbers = cleanValue.substring(2)
-
-        // Validate number length
-        if (
-          numbers.length !== 6 &&
-          numbers.length !== 8 &&
-          numbers.length !== 10
-        ) {
-          return helpers.error('string.pattern.base')
-        }
-
-        // Format with spaces: XX 123 456, XX 1234 5678, or XX 12345 67890
-        const halfLength = numbers.length / 2
-        const formattedValue = `${letters} ${numbers.substring(0, halfLength)} ${numbers.substring(halfLength)}`
-
-        // Validate the formatted value against the OS grid pattern
-        if (!osGridPattern.test(formattedValue)) {
-          return helpers.error('string.pattern.base')
-        }
-
-        // Return formatted value with spaces per GDS guidance
-        return formattedValue
-      }
+      pattern,
+      patternErrorMessage: `Enter a valid OS grid reference for ${this.title} like TQ123456`
     }
   }