diff --git a/packages/bcp/src/decode.ts b/packages/bcp/src/decode.ts
index 9fb0869a..002cc5b3 100644
--- a/packages/bcp/src/decode.ts
+++ b/packages/bcp/src/decode.ts
@@ -13,13 +13,14 @@ import {
   SendTransaction,
   SignatureBytes,
   SignedTransaction,
+  TokenTicker,
   TransactionId,
   UnsignedTransaction,
 } from "@iov/bcp";
 import { Encoding } from "@iov/encoding";
 import amino from "@tendermint/amino-js";
 
-import { coinToAmount, TokenInfos } from "./types";
+import { coinToDecimal, TokenInfos } from "./types";
 
 const { fromBase64 } = Encoding;
 
@@ -43,7 +44,12 @@ export function decodeFullSignature(signature: amino.StdSignature, nonce: number
 }
 
 export function decodeAmount(tokens: TokenInfos, coin: amino.Coin): Amount {
-  return coinToAmount(tokens, coin);
+  const [value, ticker] = coinToDecimal(tokens, coin);
+  return {
+    quantity: value.atomics,
+    fractionalDigits: value.fractionalDigits,
+    tokenTicker: ticker as TokenTicker,
+  };
 }
 
 export function parseMsg(msg: amino.Msg, chainId: ChainId, tokens: TokenInfos): SendTransaction {
diff --git a/packages/bcp/src/encode.ts b/packages/bcp/src/encode.ts
index 28843930..3ce2ebcf 100644
--- a/packages/bcp/src/encode.ts
+++ b/packages/bcp/src/encode.ts
@@ -11,10 +11,10 @@ import {
   UnsignedTransaction,
 } from "@iov/bcp";
 import { Secp256k1 } from "@iov/crypto";
-import { Encoding } from "@iov/encoding";
+import { Decimal, Encoding } from "@iov/encoding";
 import amino from "@tendermint/amino-js";
 
-import { amountToCoin, TokenInfos } from "./types";
+import { decimalToCoin, TokenInfos } from "./types";
 
 const { toBase64 } = Encoding;
 
@@ -36,7 +36,11 @@ export function encodePubkey(pubkey: PubkeyBundle): amino.PubKey {
 }
 
 export function encodeAmount(amount: Amount, tokens: TokenInfos): amino.Coin {
-  return amountToCoin(tokens, amount);
+  return decimalToCoin(
+    tokens,
+    Decimal.fromAtomics(amount.quantity, amount.fractionalDigits),
+    amount.tokenTicker,
+  );
 }
 
 export function encodeFee(fee: Fee, tokens: TokenInfos): amino.StdFee {
diff --git a/packages/bcp/src/types.ts b/packages/bcp/src/types.ts
index d4035e6c..c2f5edd1 100644
--- a/packages/bcp/src/types.ts
+++ b/packages/bcp/src/types.ts
@@ -1,31 +1,33 @@
 import { TokenInfo } from "@cosmwasm/sdk";
-import { Amount, Nonce, TokenTicker } from "@iov/bcp";
+import { Nonce } from "@iov/bcp";
+import { Decimal } from "@iov/encoding";
 import amino from "@tendermint/amino-js";
 
 export type TokenInfos = ReadonlyArray<TokenInfo>;
 
-// TODO: return null vs throw exception for undefined???
-export function amountToCoin(lookup: ReadonlyArray<TokenInfo>, amount: Amount): amino.Coin {
-  const match = lookup.find(({ ticker }) => ticker === amount.tokenTicker);
+export function decimalToCoin(lookup: readonly TokenInfo[], value: Decimal, ticker: string): amino.Coin {
+  const match = lookup.find(token => token.ticker === ticker);
   if (!match) {
-    throw Error(`unknown ticker: ${amount.tokenTicker}`);
+    throw Error(`unknown ticker: ${ticker}`);
+  }
+  if (match.fractionalDigits !== value.fractionalDigits) {
+    throw new Error(
+      "Mismatch in fractional digits between token and value. If you really want, implement a conversion here. However, this indicates a bug in the caller code.",
+    );
   }
   return {
     denom: match.denom,
-    amount: amount.quantity,
+    amount: value.atomics,
   };
 }
 
-export function coinToAmount(tokens: TokenInfos, coin: amino.Coin): Amount {
+export function coinToDecimal(tokens: readonly TokenInfo[], coin: amino.Coin): readonly [Decimal, string] {
   const match = tokens.find(({ denom }) => denom === coin.denom);
   if (!match) {
     throw Error(`unknown denom: ${coin.denom}`);
   }
-  return {
-    tokenTicker: match.ticker as TokenTicker,
-    fractionalDigits: match.fractionalDigits,
-    quantity: coin.amount,
-  };
+  const value = Decimal.fromAtomics(coin.amount, match.fractionalDigits);
+  return [value, match.ticker];
 }
 
 // tslint:disable-next-line:no-bitwise
diff --git a/packages/bcp/types/types.d.ts b/packages/bcp/types/types.d.ts
index 7191f61c..6a8f6f49 100644
--- a/packages/bcp/types/types.d.ts
+++ b/packages/bcp/types/types.d.ts
@@ -1,9 +1,17 @@
 import { TokenInfo } from "@cosmwasm/sdk";
-import { Amount, Nonce } from "@iov/bcp";
+import { Nonce } from "@iov/bcp";
+import { Decimal } from "@iov/encoding";
 import amino from "@tendermint/amino-js";
 export declare type TokenInfos = ReadonlyArray<TokenInfo>;
-export declare function amountToCoin(lookup: ReadonlyArray<TokenInfo>, amount: Amount): amino.Coin;
-export declare function coinToAmount(tokens: TokenInfos, coin: amino.Coin): Amount;
+export declare function decimalToCoin(
+  lookup: readonly TokenInfo[],
+  value: Decimal,
+  ticker: string,
+): amino.Coin;
+export declare function coinToDecimal(
+  tokens: readonly TokenInfo[],
+  coin: amino.Coin,
+): readonly [Decimal, string];
 export interface NonceInfo {
   readonly account_number: string;
   readonly sequence: string;