diff --git a/packages/bcp/src/cosmwasmconnection.spec.ts b/packages/bcp/src/cosmwasmconnection.spec.ts
index d3f3ae56..74c4f977 100644
--- a/packages/bcp/src/cosmwasmconnection.spec.ts
+++ b/packages/bcp/src/cosmwasmconnection.spec.ts
@@ -18,7 +18,7 @@ import { assert } from "@iov/utils";
 
 import { CosmWasmCodec } from "./cosmwasmcodec";
 import { CosmWasmConnection, TokenConfiguration } from "./cosmwasmconnection";
-import { signedTxJson, txId } from "./testdata.spec";
+import * as testdata from "./testdata.spec";
 
 const { fromBase64, toHex } = Encoding;
 
@@ -197,12 +197,10 @@ describe("CosmWasmConnection", () => {
   describe("identifier", () => {
     it("calculates tx hash from PostableBytes", async () => {
       pendingWithoutCosmos();
-      const codec = new CosmWasmCodec(defaultPrefix, atomConfig.bankTokens);
       const connection = await CosmWasmConnection.establish(httpUrl, defaultPrefix, atomConfig);
-      const postable = codec.bytesToPost(signedTxJson);
-      const id = await connection.identifier(postable);
+      const id = await connection.identifier(testdata.signedTxJson);
       expect(id).toMatch(/^[0-9A-F]{64}$/);
-      expect(id).toEqual(txId);
+      expect(id).toEqual(testdata.txId);
     });
   });
 
diff --git a/packages/bcp/src/cosmwasmconnection.ts b/packages/bcp/src/cosmwasmconnection.ts
index 801ec313..a44be650 100644
--- a/packages/bcp/src/cosmwasmconnection.ts
+++ b/packages/bcp/src/cosmwasmconnection.ts
@@ -1,12 +1,5 @@
 /* eslint-disable @typescript-eslint/camelcase */
-import {
-  CosmosAddressBech32Prefix,
-  CosmWasmClient,
-  RestClient,
-  TxsResponse,
-  types,
-  unmarshalTx,
-} from "@cosmwasm/sdk";
+import { CosmosAddressBech32Prefix, CosmWasmClient, RestClient, TxsResponse, types } from "@cosmwasm/sdk";
 import {
   Account,
   AccountQuery,
@@ -28,6 +21,7 @@ import {
   PostableBytes,
   PostTxResponse,
   PubkeyQuery,
+  SignedTransaction,
   Token,
   TokenTicker,
   TransactionId,
@@ -46,6 +40,7 @@ import { Stream } from "xstream";
 import { decodeCosmosPubkey, pubkeyToAddress } from "./address";
 import { Caip5 } from "./caip5";
 import { decodeAmount, parseTxsResponse } from "./decode";
+import { buildSignedTx } from "./encode";
 import { accountToNonce, BankToken, Erc20Token } from "./types";
 
 const { fromAscii, toHex } = Encoding;
@@ -162,8 +157,12 @@ export class CosmWasmConnection implements BlockchainConnection {
     return this.supportedTokens;
   }
 
-  public async identifier(signed: PostableBytes): Promise<TransactionId> {
-    const tx = unmarshalTx(signed);
+  /**
+   * This is a replacement for the unimplemented CosmWasmCodec.identifier. Here we have more
+   * context and network available, which we might use to implement the API in an async way.
+   */
+  public async identifier(signed: SignedTransaction): Promise<TransactionId> {
+    const tx = buildSignedTx(signed, this.bankTokens, this.erc20Tokens);
     // tslint:disable-next-line: deprecation
     const bytes = await this.restClient.encodeTx(tx);
     const hash = new Sha256(bytes).digest();
diff --git a/packages/bcp/types/cosmwasmconnection.d.ts b/packages/bcp/types/cosmwasmconnection.d.ts
index 6d15edea..66305e8c 100644
--- a/packages/bcp/types/cosmwasmconnection.d.ts
+++ b/packages/bcp/types/cosmwasmconnection.d.ts
@@ -14,6 +14,7 @@ import {
   PostableBytes,
   PostTxResponse,
   PubkeyQuery,
+  SignedTransaction,
   Token,
   TokenTicker,
   TransactionId,
@@ -58,7 +59,11 @@ export declare class CosmWasmConnection implements BlockchainConnection {
   height(): Promise<number>;
   getToken(searchTicker: TokenTicker): Promise<Token | undefined>;
   getAllTokens(): Promise<readonly Token[]>;
-  identifier(signed: PostableBytes): Promise<TransactionId>;
+  /**
+   * This is a replacement for the unimplemented CosmWasmCodec.identifier. Here we have more
+   * context and network available, which we might use to implement the API in an async way.
+   */
+  identifier(signed: SignedTransaction): Promise<TransactionId>;
   getAccount(query: AccountQuery): Promise<Account | undefined>;
   watchAccount(_account: AccountQuery): Stream<Account | undefined>;
   getNonce(query: AddressQuery | PubkeyQuery): Promise<Nonce>;
diff --git a/packages/sdk/src/restclient.spec.ts b/packages/sdk/src/restclient.spec.ts
index 9862d178..276de57b 100644
--- a/packages/sdk/src/restclient.spec.ts
+++ b/packages/sdk/src/restclient.spec.ts
@@ -221,9 +221,8 @@ describe("RestClient", () => {
   describe("encodeTx", () => {
     it("works for cosmoshub example", async () => {
       pendingWithoutCosmos();
-      const tx = cosmoshub.tx.value;
       const client = new RestClient(httpUrl);
-      expect(await client.encodeTx(tx)).toEqual(fromBase64(cosmoshub.tx_data));
+      expect(await client.encodeTx(cosmoshub.tx)).toEqual(fromBase64(cosmoshub.tx_data));
     });
   });
 
diff --git a/packages/sdk/src/restclient.ts b/packages/sdk/src/restclient.ts
index b6ee7e05..8815981d 100644
--- a/packages/sdk/src/restclient.ts
+++ b/packages/sdk/src/restclient.ts
@@ -9,7 +9,6 @@ import {
   isStdTx,
   Model,
   parseWasmData,
-  StdTx,
   WasmData,
 } from "./types";
 
@@ -221,8 +220,7 @@ export class RestClient {
   }
 
   /** returns the amino-encoding of the transaction performed by the server */
-  public async encodeTx(stdTx: StdTx): Promise<Uint8Array> {
-    const tx = { type: "cosmos-sdk/StdTx", value: stdTx };
+  public async encodeTx(tx: CosmosSdkTx): Promise<Uint8Array> {
     const responseData = await this.post("/txs/encode", tx);
     if (!(responseData as any).tx) {
       throw new Error("Unexpected response data format");
diff --git a/packages/sdk/types/restclient.d.ts b/packages/sdk/types/restclient.d.ts
index 8f41d03a..a7e87e27 100644
--- a/packages/sdk/types/restclient.d.ts
+++ b/packages/sdk/types/restclient.d.ts
@@ -1,4 +1,4 @@
-import { CodeInfo, ContractInfo, CosmosSdkAccount, CosmosSdkTx, Model, StdTx } from "./types";
+import { CodeInfo, ContractInfo, CosmosSdkAccount, CosmosSdkTx, Model } from "./types";
 interface NodeInfo {
   readonly network: string;
 }
@@ -92,7 +92,7 @@ export declare class RestClient {
   blocksLatest(): Promise<BlocksResponse>;
   blocks(height: number): Promise<BlocksResponse>;
   /** returns the amino-encoding of the transaction performed by the server */
-  encodeTx(stdTx: StdTx): Promise<Uint8Array>;
+  encodeTx(tx: CosmosSdkTx): Promise<Uint8Array>;
   authAccounts(address: string, height?: string): Promise<AuthAccountsResponse>;
   txs(query: string): Promise<SearchTxsResponse>;
   txsById(id: string): Promise<TxsResponse>;