diff --git a/modules/bitgo/test/v2/unit/keychains.ts b/modules/bitgo/test/v2/unit/keychains.ts
index 8a840a5ddb..07eed600e7 100644
--- a/modules/bitgo/test/v2/unit/keychains.ts
+++ b/modules/bitgo/test/v2/unit/keychains.ts
@@ -587,6 +587,28 @@ describe('V2 Keychains', function () {
         });
       });
 
+      ['tbsc'].forEach((coin) => {
+        it('should reject safe root creation when the resolved ceremony is legacy MPCv1', async function () {
+          nock(bgUrl).get('/api/v2/tss/settings').reply(200, {
+            coinSettings: {},
+          });
+          const createKeychains = sandbox
+            .stub(ECDSAUtils.EcdsaUtils.prototype, 'createKeychains')
+            .resolves(stubbedKeychainsTriplet);
+          await bitgo
+            .coin(coin)
+            .keychains()
+            .createMpc({
+              multisigType: 'tss',
+              passphrase: 'password',
+              enterprise: 'enterprise',
+              safeId: 'safeId',
+            })
+            .should.be.rejectedWith(/legacy MPCv1 ceremony/);
+          createKeychains.called.should.be.false();
+        });
+      });
+
       ['tbsc'].forEach((coin) => {
         it('should pass webauthnInfo to createKeychains for ECDSA TSS', async function () {
           nock(bgUrl).get('/api/v2/tss/settings').reply(200, {
diff --git a/modules/sdk-api/src/api.ts b/modules/sdk-api/src/api.ts
index e132426f81..05ca6a36ac 100644
--- a/modules/sdk-api/src/api.ts
+++ b/modules/sdk-api/src/api.ts
@@ -75,7 +75,10 @@ function errFromResponse<ResponseBodyType>(res: superagent.Response): ApiRespons
   const result = res.body as ResponseBodyType;
   const invalidToken = _.has(res.header, 'x-auth-required') && res.header['x-auth-required'] === 'true';
   const needsOtp = res.body?.needsOTP !== undefined;
-  return new ApiResponseError(message, status, result, invalidToken, needsOtp);
+  // Server echoes the client's `Request-ID` header (or one it generated) back on every
+  // response, including errors — surface it so failures can be correlated with server logs.
+  const requestId = res.header?.['request-id'];
+  return new ApiResponseError(message, status, result, invalidToken, needsOtp, requestId);
 }
 
 /**
diff --git a/modules/sdk-core/src/bitgo/errors.ts b/modules/sdk-core/src/bitgo/errors.ts
index b6d92b71ad..abe381799c 100644
--- a/modules/sdk-core/src/bitgo/errors.ts
+++ b/modules/sdk-core/src/bitgo/errors.ts
@@ -29,6 +29,14 @@ export class UnsupportedCoinError extends BitGoJsError {
   }
 }
 
+export class SafeMpcCeremonyUnsupportedError extends BitGoJsError {
+  public constructor(coinFamily: string) {
+    super(
+      `Cannot create Wallet Safe root keys for coin family '${coinFamily}': its TSS settings resolve to the legacy MPCv1 ceremony, which does not support safe root tagging (safeId). Enable MPCv2 for '${coinFamily}' before creating a safe with this root type.`
+    );
+  }
+}
+
 export class AddressTypeChainMismatchError extends BitGoJsError {
   constructor(addressType: string, chain: number | string) {
     super(`address type ${addressType} does not correspond to chain ${chain}`);
@@ -185,13 +193,17 @@ export class ApiResponseError<ResponseBodyType = any> extends BitGoJsError {
   result?: ResponseBodyType;
   invalidToken?: boolean;
   needsOTP?: boolean;
+  // Echoed back via the `Request-ID` response header (see logging-express's `beginLogging`),
+  // so it can be used to correlate this error with the server-side request logs.
+  requestId?: string;
 
   public constructor(
     message: string,
     status: number,
     result?: ResponseBodyType,
     invalidToken?: boolean,
-    needsOTP?: boolean
+    needsOTP?: boolean,
+    requestId?: string
   ) {
     super(message);
     this.message = message;
@@ -199,6 +211,7 @@ export class ApiResponseError<ResponseBodyType = any> extends BitGoJsError {
     this.result = result;
     this.invalidToken = invalidToken;
     this.needsOTP = needsOTP;
+    this.requestId = requestId;
   }
 }
 
diff --git a/modules/sdk-core/src/bitgo/keychain/keychains.ts b/modules/sdk-core/src/bitgo/keychain/keychains.ts
index d71e465351..63a7962efb 100644
--- a/modules/sdk-core/src/bitgo/keychain/keychains.ts
+++ b/modules/sdk-core/src/bitgo/keychain/keychains.ts
@@ -4,6 +4,7 @@ import * as _ from 'lodash';
 import * as common from '../../common';
 import { IBaseCoin, KeychainsTriplet, KeyPair } from '../baseCoin';
 import { BitGoBase } from '../bitgoBase';
+import { SafeMpcCeremonyUnsupportedError } from '../errors';
 import { decodeOrElse, ECDSAUtils, EDDSAUtils, generateRandomPassword, RequestTracer } from '../utils';
 import {
   AddKeychainOptions,
@@ -371,11 +372,20 @@ export class Keychains implements IKeychains {
     const multisigTypeVersion =
       tssSettings.coinSettings[this.baseCoin.getFamily()]?.walletCreationSettings?.multiSigTypeVersion;
 
+    const isMPCv2 = multisigTypeVersion === 'MPCv2';
+    if (params.safeId && !isMPCv2) {
+      // The legacy MPCv1 ceremonies accept a safeId for signature compatibility but silently
+      // ignore it (see EDDSAUtils.default.createKeychains / ECDSAUtils.EcdsaUtils.createKeychains),
+      // so the resulting keys never get tagged with the safe and WP's finalize step rejects them
+      // with a generic 400. Fail fast here instead of letting that confusing error surface later.
+      throw new SafeMpcCeremonyUnsupportedError(this.baseCoin.getFamily());
+    }
+
     let MpcUtils;
     if (this.baseCoin.getMPCAlgorithm() === 'eddsa') {
-      MpcUtils = multisigTypeVersion === 'MPCv2' ? EDDSAUtils.EddsaMPCv2Utils : EDDSAUtils.default;
+      MpcUtils = isMPCv2 ? EDDSAUtils.EddsaMPCv2Utils : EDDSAUtils.default;
     } else {
-      MpcUtils = multisigTypeVersion === 'MPCv2' ? ECDSAUtils.EcdsaMPCv2Utils : ECDSAUtils.EcdsaUtils;
+      MpcUtils = isMPCv2 ? ECDSAUtils.EcdsaMPCv2Utils : ECDSAUtils.EcdsaUtils;
     }
 
     const mpcUtils = new MpcUtils(this.bitgo, this.baseCoin);
diff --git a/modules/sdk-core/src/bitgo/safe/safes.ts b/modules/sdk-core/src/bitgo/safe/safes.ts
index ff499c40de..c7be05cbdd 100644
--- a/modules/sdk-core/src/bitgo/safe/safes.ts
+++ b/modules/sdk-core/src/bitgo/safe/safes.ts
@@ -16,6 +16,7 @@ import {
 import { Environments } from '../../common';
 import { IBaseCoin } from '../baseCoin';
 import { BitGoBase } from '../bitgoBase';
+import { ApiResponseError } from '../errors';
 import { decodeWithCodec } from '../utils/codecs';
 import { postWithCodec } from '../utils/postWithCodec';
 import { FinalizeSafeOptions, InitializeSafeOptions } from './iSafe';
@@ -147,7 +148,10 @@ export class Safes implements ISafes {
         hot[slots[i]] = result.value;
       } else {
         const reason = result.reason instanceof Error ? result.reason.message : String(result.reason);
-        failures.push(`${slots[i]}: ${reason}`);
+        // ApiResponseError carries the server-echoed `Request-ID` header — include it (when
+        // present) so a failed ceremony can be correlated with WP's server-side logs.
+        const requestId = result.reason instanceof ApiResponseError ? result.reason.requestId : undefined;
+        failures.push(`${slots[i]}: ${reason}${requestId ? ` (requestId: ${requestId})` : ''}`);
       }
     });