diff --git a/commitlint.config.js b/commitlint.config.js
index 9e69f2af05..8aa9ec1b32 100644
--- a/commitlint.config.js
+++ b/commitlint.config.js
@@ -59,6 +59,7 @@ module.exports = {
         'RA-',
         'SO-',
         'SC-',
+        'SI-',
         'ST-',
         'STLX-',
         'TMS-',
diff --git a/modules/abstract-eth/src/abstractEthLikeNewCoins.ts b/modules/abstract-eth/src/abstractEthLikeNewCoins.ts
index 10ee40ee17..f48a440d69 100644
--- a/modules/abstract-eth/src/abstractEthLikeNewCoins.ts
+++ b/modules/abstract-eth/src/abstractEthLikeNewCoins.ts
@@ -271,6 +271,8 @@ export type RecoverOptions = {
   derivationSeed?: string;
   apiKey?: string; // optional API key to use instead of the one from the environment
   isUnsignedSweep?: boolean; // specify if this is an unsigned recovery
+  /** For FLR P-derived wallets: the derivation path for the base address (e.g. 'm'). Defaults to 'm/0'. */
+  baseAddressDerivationPath?: string;
 } & TSSRecoverOptions;
 
 export type GetBatchExecutionInfoRT = {
@@ -2255,12 +2257,19 @@ export abstract class AbstractEthLikeNewCoins extends AbstractEthLikeCoin {
       const { gasLimit, gasPrice } = await this.getGasValues(params);
 
       const MPC = new Ecdsa();
-      const derivedCommonKeyChain = MPC.deriveUnhardened(commonKeyChain, 'm/0');
+      const derivationPath = params.baseAddressDerivationPath ?? 'm/0';
+      const derivedCommonKeyChain = MPC.deriveUnhardened(commonKeyChain, derivationPath);
       const backupKeyPair = new KeyPairLib({ pub: derivedCommonKeyChain.slice(0, 66) });
       const baseAddress = backupKeyPair.getAddress();
       const unsignedTx = (await this.buildTssRecoveryTxn(baseAddress, gasPrice, gasLimit, params)).tx;
       const messageHash = unsignedTx.getMessageToSign(true);
-      const signature = await ECDSAUtils.signRecoveryMpcV2(messageHash, userKeyShare, backupKeyShare, commonKeyChain);
+      const signature = await ECDSAUtils.signRecoveryMpcV2(
+        messageHash,
+        userKeyShare,
+        backupKeyShare,
+        commonKeyChain,
+        derivationPath
+      );
       const ethCommmon = AbstractEthLikeNewCoins.getEthLikeCommon(params.eip1559, params.replayProtectionOptions);
       const signedTx = this.getSignedTxFromSignature(ethCommmon, unsignedTx, signature);
 
diff --git a/modules/sdk-core/src/bitgo/baseCoin/iBaseCoin.ts b/modules/sdk-core/src/bitgo/baseCoin/iBaseCoin.ts
index 936d4edd3d..e5e0903c6c 100644
--- a/modules/sdk-core/src/bitgo/baseCoin/iBaseCoin.ts
+++ b/modules/sdk-core/src/bitgo/baseCoin/iBaseCoin.ts
@@ -187,6 +187,12 @@ export interface TssVerifyAddressOptions {
    * The derivation path becomes {computedPrefix}/{index} instead of m/{index}.
    */
   derivedFromParentWithSeed?: string;
+  /**
+   * Optional derivation path for the base address, from wallet.coinSpecific.baseAddressDerivationPath.
+   * When set to 'm', the base address is at the root (index 0 maps to path 'm' instead of 'm/0').
+   * Used for FLR P-derived wallets.
+   */
+  baseAddressDerivationPath?: string;
 }
 
 export function isTssVerifyAddressOptions<T extends VerifyAddressOptions | TssVerifyAddressOptions>(
@@ -262,6 +268,8 @@ export interface SupplementGenerateWalletOptions {
   subType?: 'lightningCustody' | 'lightningSelfCustody' | 'onPrem';
   coinSpecific?: { [coinName: string]: unknown };
   evmKeyRingReferenceWalletId?: string;
+  /** For FLR C wallet creation: the source FLR P wallet ID to derive from. */
+  sourceFlrpWalletId?: string;
   lightningProvider?: 'voltage' | 'amboss';
 }
 
diff --git a/modules/sdk-core/src/bitgo/utils/tss/addressVerification.ts b/modules/sdk-core/src/bitgo/utils/tss/addressVerification.ts
index 67e41d1ade..d30a584a57 100644
--- a/modules/sdk-core/src/bitgo/utils/tss/addressVerification.ts
+++ b/modules/sdk-core/src/bitgo/utils/tss/addressVerification.ts
@@ -66,7 +66,7 @@ export async function verifyMPCWalletAddress(
   isValidAddress: (address: string) => boolean,
   getAddressFromPublicKey: (publicKey: string) => string
 ): Promise<boolean> {
-  const { keychains, address, index, derivedFromParentWithSeed } = params;
+  const { keychains, address, index, derivedFromParentWithSeed, baseAddressDerivationPath } = params;
 
   if (!isValidAddress(address)) {
     throw new InvalidAddressError(`invalid address: ${address}`);
@@ -77,9 +77,15 @@ export async function verifyMPCWalletAddress(
 
   // Compute derivation path:
   // - For SMC wallets with derivedFromParentWithSeed, compute prefix and use: {prefix}/{index}
+  // - For FLR P-derived wallets where baseAddressDerivationPath is 'm', use 'm' for index 0
   // - For other wallets, use simple path: m/{index}
   const prefix = derivedFromParentWithSeed ? getDerivationPath(derivedFromParentWithSeed.toString()) : undefined;
-  const derivationPath = prefix ? `${prefix}/${index}` : `m/${index}`;
+  const numericIndex = typeof index === 'string' ? parseInt(index, 10) : index;
+  const derivationPath = prefix
+    ? `${prefix}/${index}`
+    : numericIndex === 0 && baseAddressDerivationPath === 'm'
+    ? 'm'
+    : `m/${index}`;
   const derivedPublicKey = MPC.deriveUnhardened(commonKeychain, derivationPath);
 
   // secp256k1 expects 33 bytes; ed25519 expects 32 bytes
diff --git a/modules/sdk-core/src/bitgo/utils/tss/ecdsa/ecdsaMPCv2.ts b/modules/sdk-core/src/bitgo/utils/tss/ecdsa/ecdsaMPCv2.ts
index 49980335e3..38178e9c61 100644
--- a/modules/sdk-core/src/bitgo/utils/tss/ecdsa/ecdsaMPCv2.ts
+++ b/modules/sdk-core/src/bitgo/utils/tss/ecdsa/ecdsaMPCv2.ts
@@ -756,7 +756,8 @@ export class EcdsaMPCv2Utils extends BaseEcdsaUtils {
       bufferContent = Buffer.from(txOrMessageToSign, 'hex');
     } else if (requestType === RequestType.message) {
       txOrMessageToSign = txRequest.messages![0].messageEncoded;
-      derivationPath = txRequest.messages![0].derivationPath || 'm/0';
+      derivationPath =
+        txRequest.messages![0].derivationPath || this.wallet.coinSpecific()?.baseAddressDerivationPath || 'm/0';
       bufferContent = Buffer.from(txOrMessageToSign, 'hex');
     } else {
       throw new Error('Invalid request type');
@@ -1317,21 +1318,22 @@ export async function signRecoveryMpcV2(
   messageHash: Buffer,
   userKeyShare: Buffer,
   backupKeyShare: Buffer,
-  commonKeyChain: string
+  commonKeyChain: string,
+  derivationPath = 'm/0'
 ): Promise<{
   recid: number;
   r: string;
   s: string;
   y: string;
 }> {
-  const userDsg = new DklsDsg.Dsg(userKeyShare, 0, 'm/0', messageHash);
-  const backupDsg = new DklsDsg.Dsg(backupKeyShare, 1, 'm/0', messageHash);
+  const userDsg = new DklsDsg.Dsg(userKeyShare, 0, derivationPath, messageHash);
+  const backupDsg = new DklsDsg.Dsg(backupKeyShare, 1, derivationPath, messageHash);
 
   const signatureString = DklsUtils.verifyAndConvertDklsSignature(
     messageHash,
     (await DklsUtils.executeTillRound(5, userDsg, backupDsg)) as DklsTypes.DeserializedDklsSignature,
     commonKeyChain,
-    'm/0',
+    derivationPath,
     undefined,
     false
   );
diff --git a/modules/sdk-core/src/bitgo/wallet/iWallet.ts b/modules/sdk-core/src/bitgo/wallet/iWallet.ts
index fe336d7269..43ef93c47d 100644
--- a/modules/sdk-core/src/bitgo/wallet/iWallet.ts
+++ b/modules/sdk-core/src/bitgo/wallet/iWallet.ts
@@ -352,6 +352,12 @@ export interface WalletCoinSpecific {
   /**
    * Lightning coin specific data ends
    */
+  /**
+   * For FLR P-derived wallets, the derivation path for the base address.
+   * When set to 'm', the base address is at the root (no child derivation).
+   * Defaults to 'm/0' if absent.
+   */
+  baseAddressDerivationPath?: string;
 }
 
 export interface PaginationOptions {
diff --git a/modules/sdk-core/src/bitgo/wallet/iWallets.ts b/modules/sdk-core/src/bitgo/wallet/iWallets.ts
index 02645ebc67..2b03eff9de 100644
--- a/modules/sdk-core/src/bitgo/wallet/iWallets.ts
+++ b/modules/sdk-core/src/bitgo/wallet/iWallets.ts
@@ -40,6 +40,8 @@ export interface GenerateBaseMpcWalletOptions {
   label: string;
   enterprise: string;
   walletVersion?: number;
+  /** For FLR C wallet creation: the source FLR P wallet ID to derive from. */
+  sourceFlrpWalletId?: string;
 }
 
 export interface GenerateMpcWalletOptions extends GenerateBaseMpcWalletOptions {
@@ -80,6 +82,8 @@ export interface GenerateWalletOptions {
   type?: 'hot' | 'cold' | 'custodial' | 'trading';
   subType?: 'lightningCustody' | 'lightningSelfCustody';
   evmKeyRingReferenceWalletId?: string;
+  /** For FLR C wallet creation: the source FLR P wallet ID to derive from. */
+  sourceFlrpWalletId?: string;
 }
 
 export const GenerateLightningWalletOptionsCodec = t.intersection(
diff --git a/modules/sdk-core/src/bitgo/wallet/wallets.ts b/modules/sdk-core/src/bitgo/wallet/wallets.ts
index 152a200bef..f4d7eda4ac 100644
--- a/modules/sdk-core/src/bitgo/wallet/wallets.ts
+++ b/modules/sdk-core/src/bitgo/wallet/wallets.ts
@@ -437,6 +437,7 @@ export class Wallets implements IWallets {
         originalPasscodeEncryptionCode: params.passcodeEncryptionCode,
         enterprise,
         walletVersion: params.walletVersion,
+        sourceFlrpWalletId: params.sourceFlrpWalletId,
       });
       if (params.passcodeEncryptionCode) {
         walletData.encryptedWalletPassphrase = this.bitgo.encrypt({
@@ -1485,6 +1486,7 @@ export class Wallets implements IWallets {
     enterprise,
     walletVersion,
     originalPasscodeEncryptionCode,
+    sourceFlrpWalletId,
   }: GenerateMpcWalletOptions): Promise<WalletWithKeychains> {
     if (multisigType === 'tss' && this.baseCoin.getMPCAlgorithm() === 'ecdsa') {
       const tssSettings: TssSettings = await this.bitgo
@@ -1517,6 +1519,7 @@ export class Wallets implements IWallets {
       multisigType,
       enterprise,
       walletVersion,
+      sourceFlrpWalletId,
     };
     const finalWalletParams = await this.baseCoin.supplementGenerateWallet(walletParams, keychains);
     const newWallet = await this.bitgo.post(this.baseCoin.url('/wallet/add')).send(finalWalletParams).result();
diff --git a/modules/sdk-core/test/unit/bitgo/utils/tss/addressVerification.ts b/modules/sdk-core/test/unit/bitgo/utils/tss/addressVerification.ts
index c9ce76bc84..4f21c6ea68 100644
--- a/modules/sdk-core/test/unit/bitgo/utils/tss/addressVerification.ts
+++ b/modules/sdk-core/test/unit/bitgo/utils/tss/addressVerification.ts
@@ -60,4 +60,91 @@ describe('TSS Address Verification - Derivation Path with Prefix', function () {
       });
     });
   });
+
+  describe('Derivation Path Logic for FLR P-derived wallets (baseAddressDerivationPath)', function () {
+    // Tests the path selection logic that mirrors verifyMPCWalletAddress.
+    // Written as pure logic tests to avoid the transitive module-load failures
+    // (BaseTssUtils circular init) that affect tests using getAddressVerificationModule().
+
+    function computeDerivationPath(
+      index: number | string,
+      baseAddressDerivationPath?: string,
+      derivedFromParentWithSeed?: string
+    ): string {
+      const numericIndex = typeof index === 'string' ? parseInt(index, 10) : index;
+      const prefix = derivedFromParentWithSeed ? getDerivationPath(derivedFromParentWithSeed.toString()) : undefined;
+      return prefix
+        ? `${prefix}/${index}`
+        : numericIndex === 0 && baseAddressDerivationPath === 'm'
+        ? 'm'
+        : `m/${index}`;
+    }
+
+    it('should use m/0 for index 0 when baseAddressDerivationPath is absent', function () {
+      computeDerivationPath(0).should.equal('m/0');
+    });
+
+    it('should use m for index 0 when baseAddressDerivationPath is m', function () {
+      computeDerivationPath(0, 'm').should.equal('m');
+    });
+
+    it('should use m/0 for index 0 when baseAddressDerivationPath is m/0', function () {
+      computeDerivationPath(0, 'm/0').should.equal('m/0');
+    });
+
+    it('should use m/1 for index 1 even when baseAddressDerivationPath is m', function () {
+      computeDerivationPath(1, 'm').should.equal('m/1');
+    });
+
+    it('should use m/2 for index 2 regardless of baseAddressDerivationPath', function () {
+      computeDerivationPath(2, 'm').should.equal('m/2');
+      computeDerivationPath(2).should.equal('m/2');
+    });
+
+    it('should use prefix path for SMC wallets, ignoring baseAddressDerivationPath', function () {
+      const seed = 'test-seed';
+      const expectedPrefix = getDerivationPath(seed);
+      computeDerivationPath(0, 'm', seed).should.equal(`${expectedPrefix}/0`);
+    });
+
+    it('should handle string index correctly', function () {
+      computeDerivationPath('0', 'm').should.equal('m');
+      computeDerivationPath('1', 'm').should.equal('m/1');
+    });
+
+    it('should simulate existing coin behavior: ETH, BTC, SOL without baseAddressDerivationPath always use m/N', function () {
+      // Existing coins (ETH, BTC, SOL, etc.) never set baseAddressDerivationPath.
+      // They must continue using the standard m/{index} path at every index.
+      computeDerivationPath(0, undefined).should.equal('m/0');
+      computeDerivationPath(1, undefined).should.equal('m/1');
+      computeDerivationPath(5, undefined).should.equal('m/5');
+    });
+
+    it('should simulate FLR C derived wallet: only index 0 uses m when baseAddressDerivationPath is m', function () {
+      // FLR C wallets derived from FLR P set baseAddressDerivationPath='m' in coinSpecific.
+      // The base address (index 0) must derive from root path 'm' (not 'm/0') so it matches
+      // the FLR P staking reward address.
+      computeDerivationPath(0, 'm').should.equal('m');
+      // All receive addresses (index > 0) still follow the standard m/{index} path.
+      computeDerivationPath(1, 'm').should.equal('m/1');
+      computeDerivationPath(2, 'm').should.equal('m/2');
+      computeDerivationPath(10, 'm').should.equal('m/10');
+    });
+
+    it('should confirm baseAddressDerivationPath must be exactly m to change behavior', function () {
+      // Only the exact value 'm' triggers the special path — no other value should change behavior.
+      computeDerivationPath(0, 'm/0').should.equal('m/0'); // explicit m/0 → no change
+      computeDerivationPath(0, 'M').should.equal('m/0'); // uppercase M → no change
+      computeDerivationPath(0, '').should.equal('m/0'); // empty string → no change
+    });
+
+    it('should not affect SMC/cold wallet derivation even if baseAddressDerivationPath is set', function () {
+      // When derivedFromParentWithSeed is present (SMC wallets), the prefix path takes full precedence
+      // and baseAddressDerivationPath is completely ignored.
+      const seed = 'smc-wallet-seed';
+      const expectedPrefix = getDerivationPath(seed);
+      computeDerivationPath(0, 'm', seed).should.equal(`${expectedPrefix}/0`);
+      computeDerivationPath(1, 'm', seed).should.equal(`${expectedPrefix}/1`);
+    });
+  });
 });
diff --git a/modules/sdk-core/test/unit/bitgo/utils/tss/ecdsa/ecdsaMPCv2DerivationPath.ts b/modules/sdk-core/test/unit/bitgo/utils/tss/ecdsa/ecdsaMPCv2DerivationPath.ts
new file mode 100644
index 0000000000..386d5f4c49
--- /dev/null
+++ b/modules/sdk-core/test/unit/bitgo/utils/tss/ecdsa/ecdsaMPCv2DerivationPath.ts
@@ -0,0 +1,124 @@
+import 'should';
+
+/**
+ * Tests for the derivation-path selection logic added to EcdsaMPCv2.signTssTransaction
+ * for message signing.
+ *
+ * The logic in the source file is:
+ *   derivationPath =
+ *     txRequest.messages[0].derivationPath
+ *     || wallet.coinSpecific()?.baseAddressDerivationPath
+ *     || 'm/0';
+ *
+ * These tests verify:
+ *   1. The priority order (message path > coinSpecific > default)
+ *   2. Existing coins (ETH, SOL, …) are completely unaffected — they never set
+ *      baseAddressDerivationPath, so they always get 'm/0'.
+ *   3. Only FLR C wallets derived from FLR P set baseAddressDerivationPath='m',
+ *      and only when the message has no explicit derivationPath.
+ */
+describe('EcdsaMPCv2 - Message Signing Derivation Path', function () {
+  /**
+   * Pure helper that mirrors the production fallback chain without requiring
+   * a full EcdsaMPCv2 instance (which needs heavy mocking).
+   */
+  function resolveDerivationPath(opts: {
+    messageTxDerivationPath?: string;
+    walletCoinSpecificBaseAddressDerivationPath?: string;
+  }): string {
+    return opts.messageTxDerivationPath || opts.walletCoinSpecificBaseAddressDerivationPath || 'm/0';
+  }
+
+  describe('priority order: message path > coinSpecific > default', function () {
+    it('should use txRequest message derivation path when present, ignoring coinSpecific', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: 'm/1',
+        walletCoinSpecificBaseAddressDerivationPath: 'm',
+      }).should.equal('m/1');
+    });
+
+    it('should fall back to coinSpecific baseAddressDerivationPath when message path is absent', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: 'm',
+      }).should.equal('m');
+    });
+
+    it('should fall back to m/0 when both message path and coinSpecific are absent', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: undefined,
+      }).should.equal('m/0');
+    });
+
+    it('should use message path even when coinSpecific is absent', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: 'm/3',
+        walletCoinSpecificBaseAddressDerivationPath: undefined,
+      }).should.equal('m/3');
+    });
+  });
+
+  describe('existing coins are unaffected (no baseAddressDerivationPath in coinSpecific)', function () {
+    it('ETH wallet: no baseAddressDerivationPath → always uses m/0', function () {
+      // ETH coinSpecific does not include baseAddressDerivationPath
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: undefined,
+      }).should.equal('m/0');
+    });
+
+    it('SOL wallet: no baseAddressDerivationPath → always uses m/0', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: undefined,
+      }).should.equal('m/0');
+    });
+
+    it('BTC wallet: no baseAddressDerivationPath → always uses m/0', function () {
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: undefined,
+      }).should.equal('m/0');
+    });
+
+    it('any coin that does not set baseAddressDerivationPath → always uses m/0', function () {
+      // Covers HBAR, DOT, AVAXC, POLYGON, and any future EVM-like coin
+      const coins = [undefined, null as any, ''];
+      coins.forEach((v) => {
+        resolveDerivationPath({
+          messageTxDerivationPath: undefined,
+          walletCoinSpecificBaseAddressDerivationPath: v,
+        }).should.equal('m/0');
+      });
+    });
+  });
+
+  describe('FLR C derived wallet (baseAddressDerivationPath = m)', function () {
+    it('should use m for FLR C derived wallet when no message derivation path is set', function () {
+      // FLR C wallets derived from FLR P store baseAddressDerivationPath='m' in coinSpecific.
+      // The base address must sign against root path 'm' to match the FLR P staking reward address.
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: 'm',
+      }).should.equal('m');
+    });
+
+    it('should allow an explicit message derivation path to override the FLR C coinSpecific path', function () {
+      // If the tx engine provides an explicit path (e.g. for a receive address), it wins.
+      resolveDerivationPath({
+        messageTxDerivationPath: 'm/2',
+        walletCoinSpecificBaseAddressDerivationPath: 'm',
+      }).should.equal('m/2');
+    });
+
+    it('should still use m/0 if baseAddressDerivationPath is any value other than m', function () {
+      // The special-case is strictly the value 'm'.
+      // A value of 'm/0' or any other string falls through to the default.
+      resolveDerivationPath({
+        messageTxDerivationPath: undefined,
+        walletCoinSpecificBaseAddressDerivationPath: 'm/0',
+      }).should.equal('m/0');
+    });
+  });
+});
diff --git a/modules/sdk-core/test/unit/bitgo/wallet/walletsEvmKeyring.ts b/modules/sdk-core/test/unit/bitgo/wallet/walletsEvmKeyring.ts
index 8e929bc779..fce22467fb 100644
--- a/modules/sdk-core/test/unit/bitgo/wallet/walletsEvmKeyring.ts
+++ b/modules/sdk-core/test/unit/bitgo/wallet/walletsEvmKeyring.ts
@@ -172,6 +172,71 @@ describe('Wallets', function () {
     });
   });
 
+  describe('FLR C wallet creation - sourceFlrpWalletId', function () {
+    let generateMpcWalletStub: sinon.SinonStub;
+    const mockWalletResult = {
+      wallet: { id: 'new-flrc-wallet-id' },
+      userKeychain: { id: 'user-key-id' },
+      backupKeychain: { id: 'backup-key-id' },
+      bitgoKeychain: { id: 'bitgo-key-id' },
+    };
+
+    beforeEach(function () {
+      mockBaseCoin.isEVM.returns(true);
+      mockBaseCoin.supportsTss.returns(true);
+      mockBaseCoin.getDefaultMultisigType.returns('tss');
+      // Stub the private generateMpcWallet to avoid needing full TSS key-generation mocks
+      generateMpcWalletStub = sinon.stub(wallets as any, 'generateMpcWallet').resolves(mockWalletResult);
+    });
+
+    it('should pass sourceFlrpWalletId to generateMpcWallet when provided (FLR C derived wallet)', async function () {
+      await wallets.generateWallet({
+        label: 'FLR C Wallet',
+        passphrase: 'test-passphrase',
+        multisigType: 'tss',
+        walletVersion: 3,
+        enterprise: 'test-enterprise-id',
+        sourceFlrpWalletId: 'flrp-wallet-id-123',
+      });
+
+      generateMpcWalletStub.calledOnce.should.be.true();
+      const callArgs = generateMpcWalletStub.getCall(0).args[0];
+      callArgs.should.have.property('sourceFlrpWalletId', 'flrp-wallet-id-123');
+    });
+
+    it('should NOT pass sourceFlrpWalletId for existing coins (ETH, SOL, etc.) that omit it', async function () {
+      // Existing coins like ETH and SOL never pass sourceFlrpWalletId, so it should remain
+      // undefined in the params sent to generateMpcWallet — confirming no behaviour change.
+      await wallets.generateWallet({
+        label: 'ETH TSS Wallet',
+        passphrase: 'test-passphrase',
+        multisigType: 'tss',
+        walletVersion: 3,
+        enterprise: 'test-enterprise-id',
+        // no sourceFlrpWalletId
+      });
+
+      generateMpcWalletStub.calledOnce.should.be.true();
+      const callArgs = generateMpcWalletStub.getCall(0).args[0];
+      assert.strictEqual(callArgs.sourceFlrpWalletId, undefined);
+    });
+
+    it('should pass sourceFlrpWalletId as undefined when not provided (no accidental injection)', async function () {
+      // Belt-and-suspenders: even if called with an explicit undefined, the field must stay absent
+      await wallets.generateWallet({
+        label: 'ETH TSS Wallet 2',
+        passphrase: 'test-passphrase',
+        multisigType: 'tss',
+        walletVersion: 3,
+        enterprise: 'test-enterprise-id',
+        sourceFlrpWalletId: undefined,
+      });
+
+      const callArgs = generateMpcWalletStub.getCall(0).args[0];
+      assert.strictEqual(callArgs.sourceFlrpWalletId, undefined);
+    });
+  });
+
   describe('Non-EVM chains', function () {
     beforeEach(function () {
       mockBaseCoin.isEVM.returns(false);