diff --git a/modules/sdk-coin-polyx/src/lib/iface.ts b/modules/sdk-coin-polyx/src/lib/iface.ts
index 5b007db8fe..65cb3b549d 100644
--- a/modules/sdk-coin-polyx/src/lib/iface.ts
+++ b/modules/sdk-coin-polyx/src/lib/iface.ts
@@ -12,6 +12,8 @@ export interface TxData extends Interface.TxData {
   assetId?: string;
   fromDID?: string;
   toDID?: string;
+  instructionId?: string;
+  portfolioDID?: string;
 }
 
 /**
@@ -49,6 +51,8 @@ export const MethodNames = {
   PreApproveAsset: 'preApproveAsset' as const,
 
   AddAndAffirmWithMediators: 'addAndAffirmWithMediators' as const,
+
+  RejectInstruction: 'rejectInstruction' as const,
 } as const;
 
 // Create a type that represents the keys of this object
@@ -85,6 +89,12 @@ export interface AddAndAffirmWithMediatorsArgs extends Args {
   mediators: [];
 }
 
+export interface RejectInstructionBuilderArgs extends Args {
+  id: string;
+  portfolio: { did: string; kind: PortfolioKind.Default };
+  numberOfAssets: { fungible: number; nonFungible: number; offChain: number };
+}
+
 export interface TxMethod extends Omit<Interface.TxMethod, 'args' | 'name'> {
   args:
     | Interface.TransferArgs
@@ -100,7 +110,8 @@ export interface TxMethod extends Omit<Interface.TxMethod, 'args' | 'name'> {
     | Interface.BatchArgs
     | RegisterDidWithCDDArgs
     | PreApproveAssetArgs
-    | AddAndAffirmWithMediatorsArgs;
+    | AddAndAffirmWithMediatorsArgs
+    | RejectInstructionBuilderArgs;
   name: MethodNamesValues;
 }
 
diff --git a/modules/sdk-coin-polyx/src/lib/index.ts b/modules/sdk-coin-polyx/src/lib/index.ts
index e33bdeec8f..2c936f4363 100644
--- a/modules/sdk-coin-polyx/src/lib/index.ts
+++ b/modules/sdk-coin-polyx/src/lib/index.ts
@@ -14,6 +14,7 @@ export { TransferBuilder } from './transferBuilder';
 export { RegisterDidWithCDDBuilder } from './registerDidWithCDDBuilder';
 export { PreApproveAssetBuilder } from './preApproveAssetBuilder';
 export { TokenTransferBuilder } from './tokenTransferBuilder';
+export { RejectInstructionBuilder } from './rejectInstructionBuilder';
 export { Transaction as PolyxTransaction } from './transaction';
 export { BondExtraBuilder } from './bondExtraBuilder';
 export { BatchStakingBuilder as BatchBuilder } from './batchStakingBuilder';
diff --git a/modules/sdk-coin-polyx/src/lib/rejectInstructionBuilder.ts b/modules/sdk-coin-polyx/src/lib/rejectInstructionBuilder.ts
new file mode 100644
index 0000000000..eb01557f49
--- /dev/null
+++ b/modules/sdk-coin-polyx/src/lib/rejectInstructionBuilder.ts
@@ -0,0 +1,103 @@
+import { TransactionType } from '@bitgo/sdk-core';
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { PolyxBaseBuilder } from './baseBuilder';
+import { TxMethod, MethodNames, RejectInstructionBuilderArgs, PortfolioKind } from './iface';
+import { Transaction } from './transaction';
+import { Interface } from '@bitgo/abstract-substrate';
+import { RejectInstructionTransactionSchema } from './txnSchema';
+import { DecodedSignedTx, DecodedSigningPayload, defineMethod, UnsignedTransaction } from '@substrate/txwrapper-core';
+
+export class RejectInstructionBuilder extends PolyxBaseBuilder<TxMethod, Transaction> {
+  protected _instructionId: string;
+  protected _portfolioDID: string;
+
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this._transaction = new Transaction(_coinConfig);
+  }
+
+  protected get transactionType(): TransactionType {
+    return TransactionType.RejectInstruction;
+  }
+
+  protected buildTransaction(): UnsignedTransaction {
+    const baseTxInfo = this.createBaseTxInfo();
+    return this.rejectInstruction(
+      {
+        id: this._instructionId,
+        portfolio: {
+          did: this._portfolioDID,
+          kind: PortfolioKind.Default,
+        },
+        numberOfAssets: {
+          fungible: 1,
+          nonFungible: 0,
+          offChain: 0,
+        },
+      },
+      baseTxInfo
+    );
+  }
+
+  /**
+   * @param instructionId - The ID of the instruction to be rejected
+   * @returns {this}
+   */
+  instructionId(instructionId: string): this {
+    this._instructionId = instructionId;
+    return this;
+  }
+
+  /**
+   * @param portfolioDID - The DID of the portfolio associated with the instruction
+   * @returns {this}
+   */
+  portfolioDID(portfolioDID: string): this {
+    this._portfolioDID = portfolioDID;
+    return this;
+  }
+
+  /** @inheritdoc */
+  protected fromImplementation(rawTransaction: string): Transaction {
+    const tx = super.fromImplementation(rawTransaction);
+    if (this._method?.name === MethodNames.RejectInstruction) {
+      const txMethod = this._method.args as RejectInstructionBuilderArgs;
+      this._instructionId = txMethod.id as string;
+      this._portfolioDID = txMethod.portfolio.did as string;
+    } else {
+      throw new Error(`Cannot build from transaction with method ${this._method?.name} for RejectInstructionBuilder`);
+    }
+    return tx;
+  }
+
+  /** @inheritdoc */
+  validateDecodedTransaction(decodedTxn: DecodedSigningPayload | DecodedSignedTx, rawTransaction?: string): void {
+    if (decodedTxn.method?.name === MethodNames.RejectInstruction) {
+      const txMethod = decodedTxn.method.args as RejectInstructionBuilderArgs;
+      const id = txMethod.id;
+      const portfolio = txMethod.portfolio;
+
+      const validationResult = RejectInstructionTransactionSchema.validate({
+        id,
+        portfolio,
+      });
+      if (validationResult.error) {
+        throw new Error(`Invalid transaction: ${validationResult.error.message}`);
+      }
+    }
+  }
+
+  private rejectInstruction(args: RejectInstructionBuilderArgs, info: Interface.CreateBaseTxInfo): UnsignedTransaction {
+    return defineMethod(
+      {
+        method: {
+          args,
+          name: 'rejectInstruction',
+          pallet: 'settlement',
+        },
+        ...info.baseTxInfo,
+      },
+      info.options
+    );
+  }
+}
diff --git a/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts b/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
index 3851ab44e6..741ec39513 100644
--- a/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
+++ b/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
@@ -137,7 +137,6 @@ export class TokenTransferBuilder extends PolyxBaseBuilder<TxMethod, Transaction
   validateDecodedTransaction(decodedTxn: DecodedSigningPayload | DecodedSignedTx, rawTransaction?: string): void {
     if (decodedTxn.method?.name === MethodNames.AddAndAffirmWithMediators) {
       const txMethod = decodedTxn.method.args as AddAndAffirmWithMediatorsArgs;
-      console.log(`Validating transaction: ${JSON.stringify(txMethod)}`);
       const venueId = txMethod.venueId;
       const settlementType = txMethod.settlementType;
       const tradeDate = txMethod.tradeDate;
diff --git a/modules/sdk-coin-polyx/src/lib/transaction.ts b/modules/sdk-coin-polyx/src/lib/transaction.ts
index 9a0b7570dc..563d94dc3c 100644
--- a/modules/sdk-coin-polyx/src/lib/transaction.ts
+++ b/modules/sdk-coin-polyx/src/lib/transaction.ts
@@ -2,7 +2,14 @@ import { Transaction as SubstrateTransaction, utils, KeyPair } from '@bitgo/abst
 import { InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
 import { construct, decode } from '@substrate/txwrapper-polkadot';
 import { decodeAddress } from '@polkadot/keyring';
-import { DecodedTx, RegisterDidWithCDDArgs, PreApproveAssetArgs, TxData, AddAndAffirmWithMediatorsArgs } from './iface';
+import {
+  DecodedTx,
+  RegisterDidWithCDDArgs,
+  PreApproveAssetArgs,
+  TxData,
+  AddAndAffirmWithMediatorsArgs,
+  RejectInstructionBuilderArgs,
+} from './iface';
 import polyxUtils from './utils';
 
 export class Transaction extends SubstrateTransaction {
@@ -63,6 +70,11 @@ export class Transaction extends SubstrateTransaction {
       result.amount = sendTokenArgs.legs[0].fungible.amount.toString();
       result.assetId = sendTokenArgs.legs[0].fungible.assetId;
       result.memo = sendTokenArgs.instructionMemo;
+    } else if (this.type === TransactionType.RejectInstruction) {
+      const rejectInstructionArgs = txMethod as RejectInstructionBuilderArgs;
+      result.instructionId = rejectInstructionArgs.id as string;
+      result.portfolioDID = rejectInstructionArgs.portfolio.did as string;
+      result.amount = '0'; // Reject instruction does not transfer any value
     } else {
       return super.toJson() as TxData;
     }
@@ -88,6 +100,8 @@ export class Transaction extends SubstrateTransaction {
       this.decodeInputsAndOutputsForPreApproveAsset(decodedTx);
     } else if (this.type === TransactionType.SendToken) {
       this.decodeInputsAndOutputsForSendToken(decodedTx);
+    } else if (this.type === TransactionType.RejectInstruction) {
+      this.decodeInputsAndOutputsForRejectInstruction(decodedTx);
     }
   }
 
@@ -148,4 +162,22 @@ export class Transaction extends SubstrateTransaction {
       coin: this._coinConfig.name,
     });
   }
+
+  private decodeInputsAndOutputsForRejectInstruction(decodedTx: DecodedTx) {
+    const txMethod = decodedTx.method.args as RejectInstructionBuilderArgs;
+    const portfolioDID = txMethod.portfolio.did;
+    const value = '0'; // Reject instruction does not transfer any value
+
+    this._inputs.push({
+      address: portfolioDID,
+      value,
+      coin: this._coinConfig.name,
+    });
+
+    this._outputs.push({
+      address: portfolioDID,
+      value,
+      coin: this._coinConfig.name,
+    });
+  }
 }
diff --git a/modules/sdk-coin-polyx/src/lib/txnSchema.ts b/modules/sdk-coin-polyx/src/lib/txnSchema.ts
index 438e0e0879..99a75b6fe4 100644
--- a/modules/sdk-coin-polyx/src/lib/txnSchema.ts
+++ b/modules/sdk-coin-polyx/src/lib/txnSchema.ts
@@ -93,6 +93,27 @@ export const AddAndAffirmWithMediatorsTransactionSchema = joi.object({
   mediators: joi.array().length(0).required(),
 });
 
+export const RejectInstructionTransactionSchema = joi.object({
+  id: joi.string().required(),
+  portfolio: joi
+    .object({
+      did: addressSchema.required(),
+      kind: joi
+        .object({
+          default: joi.valid(null),
+        })
+        .required(),
+    })
+    .required(),
+  numberOfAssets: joi
+    .object({
+      fungible: joi.number().required(),
+      nonFungible: joi.number().required(),
+      offChain: joi.number().required(),
+    })
+    .optional(),
+});
+
 // For standalone bondExtra transactions
 export const BondExtraTransactionSchema = joi.object({
   value: joi.string().required(),
diff --git a/modules/sdk-coin-polyx/test/resources/index.ts b/modules/sdk-coin-polyx/test/resources/index.ts
index cd9e53d04d..c3890b12ea 100644
--- a/modules/sdk-coin-polyx/test/resources/index.ts
+++ b/modules/sdk-coin-polyx/test/resources/index.ts
@@ -91,6 +91,12 @@ export const rawTx = {
     unsigned:
       '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',
   },
+  rejectInstruction: {
+    signed:
+      '0x49028400e8164bbe81964be28292d96f62c2ef6117d911638f38ae1b1bbe69df0b6df127004a08d9ccbb4b157c3df4b3e7a8bc602e6f5fab075a4bf36b29963a9a8926d16b280c2e514e534d42bcf3173372c619449c595d6183a9fbe5f9a8efe9c5b6100965034800250d14370000000000001208d7851e6698249aea40742701ee1ef6cdcced260a7c49c1cca1a9db83634200',
+    unsigned:
+      '0xac250d14370000000000001208d7851e6698249aea40742701ee1ef6cdcced260a7c49c1cca1a9db8363420025014c007bdb6a00070000002ace05e703aa50b48c0ccccfc8b424f7aab9a1e2c424ed12e45d20b1e8ffd0d6ffecb4672251137ef38c9aca7c031e578ae13c376c1699fc9cc094c29e16c7df',
+  },
 };
 
 export const stakingTx = {
diff --git a/modules/sdk-coin-polyx/test/unit/transactionBuilder/rejectInstructionBuilder.ts b/modules/sdk-coin-polyx/test/unit/transactionBuilder/rejectInstructionBuilder.ts
new file mode 100644
index 0000000000..454aa0906c
--- /dev/null
+++ b/modules/sdk-coin-polyx/test/unit/transactionBuilder/rejectInstructionBuilder.ts
@@ -0,0 +1,133 @@
+import should from 'should';
+import { RejectInstructionBuilder } from '../../../src/lib';
+import { utils } from '../../../src';
+
+import { accounts, rawTx, chainName, genesisHash, mockTssSignature } from '../../resources';
+import { buildTestConfig } from './base';
+import { testnetMaterial } from '../../../src/resources';
+
+describe('Polyx Reject Instruction Builder - Testnet', () => {
+  let builder: RejectInstructionBuilder;
+
+  const sender = accounts.account1;
+  const instructionId = '14100';
+  const portfolioDID = '0x1208d7851e6698249aea40742701ee1ef6cdcced260a7c49c1cca1a9db836342';
+
+  beforeEach(() => {
+    const config = buildTestConfig();
+    builder = new RejectInstructionBuilder(config).material(utils.getMaterial(config.network.type));
+  });
+
+  describe('build rejectInstruction transaction', () => {
+    it('should build a rejectInstruction transaction', async () => {
+      builder
+        .instructionId(instructionId)
+        .portfolioDID(portfolioDID)
+        .sender({ address: sender.address })
+        .validity({ firstValid: 3933, maxDuration: 64 })
+        .referenceBlock('0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d')
+        .sequenceId({ name: 'Nonce', keyword: 'nonce', value: 200 })
+        .fee({ amount: 0, type: 'tip' });
+      builder.addSignature({ pub: sender.publicKey }, Buffer.from(mockTssSignature, 'hex'));
+      const tx = await builder.build();
+      const txJson = tx.toJson();
+      should.deepEqual(txJson.instructionId, instructionId);
+      should.deepEqual(txJson.portfolioDID, portfolioDID);
+      should.deepEqual(txJson.sender, sender.address);
+      should.deepEqual(txJson.blockNumber, 3933);
+      should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
+      should.deepEqual(txJson.genesisHash, genesisHash);
+      should.deepEqual(txJson.specVersion, Number(testnetMaterial.specVersion));
+      should.deepEqual(txJson.nonce, 200);
+      should.deepEqual(txJson.tip, 0);
+      should.deepEqual(txJson.transactionVersion, Number(testnetMaterial.txVersion));
+      should.deepEqual(txJson.chainName, testnetMaterial.chainName);
+      should.deepEqual(txJson.eraPeriod, 64);
+    });
+
+    it('should build an unsigned rejectInstruction transaction', async () => {
+      builder
+        .instructionId(instructionId)
+        .portfolioDID(portfolioDID)
+        .sender({ address: sender.address })
+        .validity({ firstValid: 3933, maxDuration: 64 })
+        .referenceBlock('0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d')
+        .sequenceId({ name: 'Nonce', keyword: 'nonce', value: 200 })
+        .fee({ amount: 0, type: 'tip' });
+      const tx = await builder.build();
+      const txJson = tx.toJson();
+      should.deepEqual(txJson.instructionId, instructionId);
+      should.deepEqual(txJson.portfolioDID, portfolioDID);
+      should.deepEqual(txJson.sender, sender.address);
+      should.deepEqual(txJson.blockNumber, 3933);
+      should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
+      should.deepEqual(txJson.genesisHash, genesisHash);
+      should.deepEqual(txJson.specVersion, Number(testnetMaterial.specVersion));
+      should.deepEqual(txJson.nonce, 200);
+      should.deepEqual(txJson.tip, 0);
+      should.deepEqual(txJson.transactionVersion, Number(testnetMaterial.txVersion));
+      should.deepEqual(txJson.chainName, chainName);
+      should.deepEqual(txJson.eraPeriod, 64);
+    });
+
+    it('should build from raw signed tx', async () => {
+      if (rawTx.rejectInstruction?.signed) {
+        builder.from(rawTx.rejectInstruction.signed);
+        builder
+          .validity({ firstValid: 3933, maxDuration: 64 })
+          .referenceBlock('0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
+        const tx = await builder.build();
+        const txJson = tx.toJson();
+        should.exist(txJson.instructionId);
+        should.deepEqual(txJson.instructionId, instructionId);
+        should.exist(txJson.portfolioDID);
+        should.deepEqual(txJson.portfolioDID, portfolioDID);
+        should.deepEqual(txJson.blockNumber, 3933);
+        should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
+        should.deepEqual(txJson.genesisHash, genesisHash);
+        should.deepEqual(txJson.specVersion, Number(testnetMaterial.specVersion));
+        should.deepEqual(txJson.transactionVersion, Number(testnetMaterial.txVersion));
+        should.deepEqual(txJson.chainName, chainName);
+        should.deepEqual(txJson.eraPeriod, 64);
+      }
+    });
+
+    it('should build from raw unsigned tx', async () => {
+      if (rawTx.rejectInstruction?.unsigned) {
+        builder.from(rawTx.rejectInstruction.unsigned);
+        builder
+          .validity({ firstValid: 3933, maxDuration: 64 })
+          .referenceBlock('0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d')
+          .sender({ address: sender.address })
+          .addSignature({ pub: sender.publicKey }, Buffer.from(mockTssSignature, 'hex'));
+
+        const tx = await builder.build();
+        const txJson = tx.toJson();
+        should.exist(txJson.instructionId);
+        should.deepEqual(txJson.instructionId, instructionId);
+        should.exist(txJson.portfolioDID);
+        should.deepEqual(txJson.portfolioDID, portfolioDID);
+        should.deepEqual(txJson.sender, sender.address);
+        should.deepEqual(txJson.blockNumber, 3933);
+        should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
+        should.deepEqual(txJson.genesisHash, genesisHash);
+        should.deepEqual(txJson.specVersion, Number(testnetMaterial.specVersion));
+        should.deepEqual(txJson.eraPeriod, 64);
+        should.deepEqual(txJson.transactionVersion, Number(testnetMaterial.txVersion));
+        should.deepEqual(txJson.chainName, chainName);
+      }
+    });
+
+    it('should validate instruction ID is set', async () => {
+      builder
+        .portfolioDID(portfolioDID)
+        .sender({ address: sender.address })
+        .validity({ firstValid: 3933, maxDuration: 64 })
+        .referenceBlock('0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d')
+        .sequenceId({ name: 'Nonce', keyword: 'nonce', value: 200 })
+        .fee({ amount: 0, type: 'tip' });
+
+      await builder.build().should.be.rejected();
+    });
+  });
+});
diff --git a/modules/sdk-core/src/account-lib/baseCoin/enum.ts b/modules/sdk-core/src/account-lib/baseCoin/enum.ts
index f5cb498b58..89c2fd8ab0 100644
--- a/modules/sdk-core/src/account-lib/baseCoin/enum.ts
+++ b/modules/sdk-core/src/account-lib/baseCoin/enum.ts
@@ -107,6 +107,9 @@ export enum TransactionType {
 
   // cspr
   stakingUnlock,
+
+  // polyx
+  RejectInstruction,
 }
 
 /**