diff --git a/__tests__/unit/services/wallet.spec.js b/__tests__/unit/services/wallet.spec.js
index f40e0020af..62bf960614 100644
--- a/__tests__/unit/services/wallet.spec.js
+++ b/__tests__/unit/services/wallet.spec.js
@@ -50,4 +50,85 @@ describe('Services > Wallet', () => {
       expect(WalletService.getAddress(passphrase, 30)).toEqual(address)
     })
   })
+
+  describe('validateUsername', () => {
+    it('should work OK', () => {
+      const username = 'example'
+      expect(WalletService.validateUsername(username)).toEqual({
+        passes: true,
+        errors: []
+      })
+    })
+
+    it('should not be empty', () => {
+      const username = ''
+      expect(WalletService.validateUsername(username)).toEqual({
+        passes: false,
+        errors: [{ type: 'empty' }]
+      })
+    })
+
+    it('should admit 20 characters at most', () => {
+      const username = 'asdf1234asdf1234asdf1234'
+      expect(WalletService.validateUsername(username)).toEqual({
+        passes: false,
+        errors: [{ type: 'maxLength' }]
+      })
+    })
+
+    it('should not admit uppercase characters', () => {
+      const username = 'eXamPLe'
+      expect(WalletService.validateUsername(username)).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+    })
+
+    it('should admit only alphanumeric characters and some symbols', () => {
+      expect(WalletService.validateUsername('a!5@$&_.')).toEqual({
+        passes: true,
+        errors: []
+      })
+
+      expect(WalletService.validateUsername('~ll')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a#')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a%0')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('(a)')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a}a{')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a[a]')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a+a')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+
+      expect(WalletService.validateUsername('a-a')).toEqual({
+        passes: false,
+        errors: [{ type: 'invalidFormat' }]
+      })
+    })
+  })
 })
diff --git a/src/renderer/components/Transaction/TransactionConfirm/TransactionConfirmDelegateRegistration.vue b/src/renderer/components/Transaction/TransactionConfirm/TransactionConfirmDelegateRegistration.vue
index 97ba1fda0a..fbb0d2c8dd 100644
--- a/src/renderer/components/Transaction/TransactionConfirm/TransactionConfirmDelegateRegistration.vue
+++ b/src/renderer/components/Transaction/TransactionConfirm/TransactionConfirmDelegateRegistration.vue
@@ -32,16 +32,18 @@ export default {
     ListDividedItem
   },
 
+  computed: {
+    senderLabel () {
+      return this.wallet_formatAddress(this.currentWallet.address)
+    }
+  },
+
   methods: {
     getUsername (transaction) {
       if (transaction.asset && transaction.asset.delegate) {
         return transaction.asset.delegate.username
       }
       return ''
-    },
-
-    senderLabel () {
-      return this.wallet_formatAddress(this.currentWallet.address)
     }
   }
 }
diff --git a/src/renderer/components/Transaction/TransactionForm/TransactionFormDelegateRegistration.vue b/src/renderer/components/Transaction/TransactionForm/TransactionFormDelegateRegistration.vue
index a78482fb7f..ed84a98c06 100644
--- a/src/renderer/components/Transaction/TransactionForm/TransactionFormDelegateRegistration.vue
+++ b/src/renderer/components/Transaction/TransactionForm/TransactionFormDelegateRegistration.vue
@@ -218,26 +218,25 @@ export default {
         }
       },
       username: {
-        required,
         isValid (value) {
           const validation = WalletService.validateUsername(value)
-          if (validation && validation.passes) {
-            this.error = null
-            return validation.passes
-          }
 
-          if (validation.errors && validation.errors.length) {
-            const { type } = validation.errors[0]
-            if (type === 'string.max') {
-              this.error = this.$t('WALLET_DELEGATES.USERNAME_MAX_LENGTH_ERROR')
-            } else {
-              this.error = this.$t('WALLET_DELEGATES.USERNAME_ERROR')
-            }
+          if (validation.passes) {
+            this.error = null
           } else {
-            this.error = this.$t('WALLET_DELEGATES.USERNAME_ERROR')
+            switch (validation.errors[0].type) {
+              case 'empty':
+                this.error = this.$t('WALLET_DELEGATES.USERNAME_EMPTY_ERROR')
+                break
+              case 'maxLength':
+                this.error = this.$t('WALLET_DELEGATES.USERNAME_MAX_LENGTH_ERROR')
+                break
+              default:
+                this.error = this.$t('WALLET_DELEGATES.USERNAME_ERROR')
+            }
           }
 
-          return false
+          return validation.passes
         }
       },
       passphrase: {
diff --git a/src/renderer/i18n/locales/en-US.js b/src/renderer/i18n/locales/en-US.js
index e6dd1f7a52..1e229a18d0 100644
--- a/src/renderer/i18n/locales/en-US.js
+++ b/src/renderer/i18n/locales/en-US.js
@@ -923,6 +923,7 @@ export default {
     UNVOTE: 'Unvote',
     VOTES: 'Votes',
     VOTE: 'Vote',
+    USERNAME_EMPTY_ERROR: 'The username must have at least 1 character',
     USERNAME_ERROR: 'No special characters or uppercase allowed',
     USERNAME_MAX_LENGTH_ERROR: 'The username must be less than or equal to 20 characters long',
     ALREADY_REGISTERED: 'This wallet is already registered as a delegate',
diff --git a/src/renderer/services/wallet.js b/src/renderer/services/wallet.js
index 61bb88d06c..13cf232457 100644
--- a/src/renderer/services/wallet.js
+++ b/src/renderer/services/wallet.js
@@ -1,5 +1,5 @@
 import bip39 from 'bip39'
-import { crypto, Message, validator } from '@arkecosystem/crypto'
+import { crypto, Message } from '@arkecosystem/crypto'
 import { version as mainnetVersion } from '@config/networks/mainnet'
 import axios from 'axios'
 
@@ -139,11 +139,24 @@ export default class WalletService {
    * Check that a username is valid
    *
    * @param {String} username
-   * @return {Object} { data: String, errors: Array, passes: Boolean, fails: Error }
+   * @return {Object} { errors: Array, passes: Boolean }
    */
   static validateUsername (username) {
-    if (!username) return
-    return validator.rules.username(username)
+    let errors = []
+
+    if (username.length < 1) {
+      errors.push({ type: 'empty' })
+    } else if (username.length > 20) {
+      errors.push({ type: 'maxLength' })
+    // Regex from `@arkecosystem/crypto`
+    } else if (!username.match(/^[a-z0-9!@$&_.]+$/)) {
+      errors.push({ type: 'invalidFormat' })
+    }
+
+    return {
+      errors,
+      passes: errors.length === 0
+    }
   }
 
   /**