diff --git a/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts b/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
index 741ec39513..2501a895c5 100644
--- a/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
+++ b/modules/sdk-coin-polyx/src/lib/tokenTransferBuilder.ts
@@ -84,14 +84,25 @@ export class TokenTransferBuilder extends PolyxBaseBuilder<TxMethod, Transaction
 
   /**
    * Sets the memo for the transaction.
-   * Pads the memo on the left with zeros to ensure it is 32 characters long.
+   * Encodes the memo as UTF-8 bytes right-padded with zero bytes to 32 bytes,
+   * matching the Polymesh Memo type ([u8; 32]).
    *
    * @param {string} memo - The memo for the transaction.
    * @returns {this} The current instance of the builder.
    */
   memo(memo: string): this {
-    const paddedMemo = memo.padStart(32, '0');
-    this._memo = paddedMemo;
+    // fromImplementation passes the decoded on-chain hex (0x + 64 hex chars) — pass through unchanged
+    if (/^0x[0-9a-fA-F]{64}$/.test(memo)) {
+      this._memo = memo;
+      return this;
+    }
+    const memoBytes = Buffer.from(memo, 'utf8');
+    if (memoBytes.length > 32) {
+      throw new Error('Memo must be 32 bytes or fewer when UTF-8 encoded');
+    }
+    const paddedBuffer = Buffer.alloc(32, 0);
+    memoBytes.copy(paddedBuffer, 0);
+    this._memo = '0x' + paddedBuffer.toString('hex');
     return this;
   }
 
diff --git a/modules/sdk-coin-polyx/src/lib/transferBuilder.ts b/modules/sdk-coin-polyx/src/lib/transferBuilder.ts
index 2fe9d5c3ca..dbcfb8049a 100644
--- a/modules/sdk-coin-polyx/src/lib/transferBuilder.ts
+++ b/modules/sdk-coin-polyx/src/lib/transferBuilder.ts
@@ -69,14 +69,25 @@ export class TransferBuilder extends PolyxBaseBuilder<TxMethod, Transaction> {
 
   /**
    * The memo to attach to the transfer transaction.
-   * Pads the memo on the left with zeros to ensure it is 32 characters long.
+   * Encodes the memo as UTF-8 bytes right-padded with zero bytes to 32 bytes,
+   * matching the Polymesh Memo type ([u8; 32]).
    *
    * @param {string} memo The memo string to include.
    * @returns {TransferBuilder} This transfer builder.
    */
   memo(memo: string): this {
-    const paddedMemo = memo.padStart(32, '0');
-    this._memo = paddedMemo;
+    // fromImplementation passes the decoded on-chain hex (0x + 64 hex chars) — pass through unchanged
+    if (/^0x[0-9a-fA-F]{64}$/.test(memo)) {
+      this._memo = memo;
+      return this;
+    }
+    const memoBytes = Buffer.from(memo, 'utf8');
+    if (memoBytes.length > 32) {
+      throw new Error('Memo must be 32 bytes or fewer when UTF-8 encoded');
+    }
+    const paddedBuffer = Buffer.alloc(32, 0);
+    memoBytes.copy(paddedBuffer, 0);
+    this._memo = '0x' + paddedBuffer.toString('hex');
     return this;
   }
 
diff --git a/modules/sdk-coin-polyx/test/unit/transactionBuilder/tokenTransferBuilder.ts b/modules/sdk-coin-polyx/test/unit/transactionBuilder/tokenTransferBuilder.ts
index fd1ccc5b9c..4a7bde567c 100644
--- a/modules/sdk-coin-polyx/test/unit/transactionBuilder/tokenTransferBuilder.ts
+++ b/modules/sdk-coin-polyx/test/unit/transactionBuilder/tokenTransferBuilder.ts
@@ -40,7 +40,7 @@ describe('Polyx token transfer Builder - Testnet', () => {
       should.deepEqual(txJson.fromDID, senderDID);
       should.deepEqual(txJson.sender, sender.address);
       should.deepEqual(txJson.assetId, assetId);
-      should.deepEqual(txJson.memo, '0x3030303030303030303030303030303030303030303030303030303030303030');
+      should.deepEqual(txJson.memo, '0x3000000000000000000000000000000000000000000000000000000000000000');
       should.deepEqual(txJson.blockNumber, 3933);
       should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
       should.deepEqual(txJson.genesisHash, genesisHash);
@@ -79,7 +79,7 @@ describe('Polyx token transfer Builder - Testnet', () => {
       should.deepEqual(txJson.fromDID, senderDID);
       should.deepEqual(txJson.sender, sender.address);
       should.deepEqual(txJson.assetId, assetId);
-      should.deepEqual(txJson.memo, '0x3030303030303030303030303030303030303030303030303030303030303030');
+      should.deepEqual(txJson.memo, '0x3000000000000000000000000000000000000000000000000000000000000000');
       should.deepEqual(txJson.blockNumber, 3933);
       should.deepEqual(txJson.referenceBlock, '0x149799bc9602cb5cf201f3425fb8d253b2d4e61fc119dcab3249f307f594754d');
       should.deepEqual(txJson.genesisHash, genesisHash);