diff --git a/modules/sdk-coin-canton/src/lib/constant.ts b/modules/sdk-coin-canton/src/lib/constant.ts
index 789ba64a4d..0fefb27d03 100644
--- a/modules/sdk-coin-canton/src/lib/constant.ts
+++ b/modules/sdk-coin-canton/src/lib/constant.ts
@@ -12,3 +12,5 @@ export const SigningAlgorithmSpec = {
 
 export const PUBLIC_KEY_FORMAT = 'CRYPTO_KEY_FORMAT_RAW';
 export const PUBLIC_KEY_SPEC = 'SIGNING_KEY_SPEC_EC_CURVE25519';
+export const SIGNATURE_FORMAT = 'SIGNATURE_FORMAT_RAW';
+export const SIGNATURE_ALGORITHM_SPEC = 'SIGNING_ALGORITHM_SPEC_ED25519';
diff --git a/modules/sdk-coin-canton/src/lib/iface.ts b/modules/sdk-coin-canton/src/lib/iface.ts
index 24a79c56bd..ffda04ef8b 100644
--- a/modules/sdk-coin-canton/src/lib/iface.ts
+++ b/modules/sdk-coin-canton/src/lib/iface.ts
@@ -64,3 +64,20 @@ export interface OneStepEnablementRequest {
   actAs: string[];
   readAs: string[];
 }
+
+export interface OnboardingTransaction {
+  transaction: string;
+}
+
+export interface MultiHashSignature {
+  format: string;
+  signature: string;
+  signedBy: string;
+  signingAlgorithmSpec: string;
+}
+
+export interface WalletInitBroadcastData {
+  preparedParty: PreparedParty;
+  onboardingTransactions: OnboardingTransaction[];
+  multiHashSignatures: MultiHashSignature[];
+}
diff --git a/modules/sdk-coin-canton/src/lib/walletInitBuilder.ts b/modules/sdk-coin-canton/src/lib/walletInitBuilder.ts
index 6939c5c103..291a0d74cc 100644
--- a/modules/sdk-coin-canton/src/lib/walletInitBuilder.ts
+++ b/modules/sdk-coin-canton/src/lib/walletInitBuilder.ts
@@ -1,6 +1,14 @@
 import BigNumber from 'bignumber.js';
 
-import { BaseAddress, BaseKey, BaseTransactionBuilder, BuildTransactionError } from '@bitgo/sdk-core';
+import {
+  BaseAddress,
+  BaseKey,
+  BaseTransactionBuilder,
+  BuildTransactionError,
+  InvalidTransactionError,
+  PublicKey,
+  Signature,
+} from '@bitgo/sdk-core';
 import { BaseCoin as CoinConfig } from '@bitgo/statics';
 
 import { KeyPair } from './keyPair';
@@ -11,6 +19,7 @@ import { PUBLIC_KEY_FORMAT, PUBLIC_KEY_SPEC } from './constant';
 
 export class WalletInitBuilder extends BaseTransactionBuilder {
   private _transaction: WalletInitTransaction;
+  private _signatures: Signature[] = [];
 
   private _publicKey: IPublicKey;
   private _partyHint: string;
@@ -91,6 +100,15 @@ export class WalletInitBuilder extends BaseTransactionBuilder {
     throw new Error('Not implemented');
   }
 
+  /** @inheritDoc */
+  addSignature(publicKey: PublicKey, signature: Buffer): void {
+    if (!this.transaction) {
+      throw new InvalidTransactionError('transaction is empty!');
+    }
+    this._signatures.push({ publicKey, signature });
+    this.transaction.signatures = signature.toString('base64');
+  }
+
   /**
    * Sets the public key used for signing.
    *
diff --git a/modules/sdk-coin-canton/src/lib/walletInitialization/walletInitTransaction.ts b/modules/sdk-coin-canton/src/lib/walletInitialization/walletInitTransaction.ts
index fe108d7259..6e536aa0b6 100644
--- a/modules/sdk-coin-canton/src/lib/walletInitialization/walletInitTransaction.ts
+++ b/modules/sdk-coin-canton/src/lib/walletInitialization/walletInitTransaction.ts
@@ -1,6 +1,13 @@
 import { BaseKey, BaseTransaction, InvalidTransactionError, TransactionType } from '@bitgo/sdk-core';
 import { BaseCoin as CoinConfig } from '@bitgo/statics';
-import { PreparedParty, WalletInitTxData } from '../iface';
+import {
+  MultiHashSignature,
+  OnboardingTransaction,
+  PreparedParty,
+  WalletInitBroadcastData,
+  WalletInitTxData,
+} from '../iface';
+import { SIGNATURE_ALGORITHM_SPEC, SIGNATURE_FORMAT } from '../constant';
 
 export class WalletInitTransaction extends BaseTransaction {
   private _preparedParty: PreparedParty;
@@ -31,7 +38,29 @@ export class WalletInitTransaction extends BaseTransaction {
     if (!this._preparedParty) {
       throw new InvalidTransactionError('Empty transaction data');
     }
-    return Buffer.from(JSON.stringify(this._preparedParty)).toString('base64');
+    const multiHashSignatures: MultiHashSignature[] = [];
+    if (this.signature.length > 0) {
+      this.signature.map((signature) => {
+        const multiHashSignature: MultiHashSignature = {
+          format: SIGNATURE_FORMAT,
+          signature: signature,
+          signedBy: this._preparedParty.publicKeyFingerprint,
+          signingAlgorithmSpec: SIGNATURE_ALGORITHM_SPEC,
+        };
+        multiHashSignatures.push(multiHashSignature);
+      });
+    }
+    const walletInitBroadcastData: WalletInitBroadcastData = {
+      preparedParty: this._preparedParty,
+      onboardingTransactions: this._preparedParty.topologyTransactions.map((txn) => {
+        const onboardingTransaction: OnboardingTransaction = {
+          transaction: txn,
+        };
+        return onboardingTransaction;
+      }),
+      multiHashSignatures: multiHashSignatures,
+    };
+    return Buffer.from(JSON.stringify(walletInitBroadcastData)).toString('base64');
   }
 
   toJson(): WalletInitTxData {
@@ -55,10 +84,15 @@ export class WalletInitTransaction extends BaseTransaction {
 
   fromRawTransaction(rawTx: string): void {
     try {
-      const decoded: PreparedParty = JSON.parse(Buffer.from(rawTx, 'base64').toString('utf8'));
-      this._preparedParty = decoded;
+      const decoded: WalletInitBroadcastData = JSON.parse(Buffer.from(rawTx, 'base64').toString('utf8'));
+      this._preparedParty = decoded.preparedParty;
       this._type = TransactionType.WalletInitialization;
-      this._id = decoded.multiHash;
+      this._id = decoded.preparedParty.multiHash;
+      if (decoded.multiHashSignatures.length > 0) {
+        decoded.multiHashSignatures.map((multiHashSignature: MultiHashSignature) => {
+          this.signatures = multiHashSignature.signature;
+        });
+      }
     } catch (e) {
       throw new InvalidTransactionError('Unable to parse raw transaction data');
     }
diff --git a/modules/sdk-coin-canton/test/unit/builder/walletInit/walletInitBuilder.ts b/modules/sdk-coin-canton/test/unit/builder/walletInit/walletInitBuilder.ts
index 12d2ac8e34..173a66f6d2 100644
--- a/modules/sdk-coin-canton/test/unit/builder/walletInit/walletInitBuilder.ts
+++ b/modules/sdk-coin-canton/test/unit/builder/walletInit/walletInitBuilder.ts
@@ -3,8 +3,7 @@ import should from 'should';
 
 import { coins } from '@bitgo/statics';
 
-import { WalletInitBuilder } from '../../../../src/lib/walletInitBuilder';
-import { WalletInitTransaction } from '../../../../src/lib/walletInitialization/walletInitTransaction';
+import { WalletInitBuilder, WalletInitTransaction } from '../../../../src';
 import { WalletInitRequest } from '../../../../src/lib/iface';
 
 import { GenerateTopologyResponse, InvalidGenerateTopologyResponse, WalletInitRequestData } from '../../../resources';