diff --git a/src/families/cosmos/js-buildTransaction.ts b/src/families/cosmos/js-buildTransaction.ts
index 4b86597563..66b932f1ad 100644
--- a/src/families/cosmos/js-buildTransaction.ts
+++ b/src/families/cosmos/js-buildTransaction.ts
@@ -1,7 +1,22 @@
 import { Account } from "../../types";
 import { Transaction } from "./types";
+import {
+  makeAuthInfoBytes,
+  Registry,
+  TxBodyEncodeObject,
+} from "@cosmjs/proto-signing";
+import {
+  MsgDelegate,
+  MsgUndelegate,
+  MsgBeginRedelegate,
+} from "cosmjs-types/cosmos/staking/v1beta1/tx";
+import { MsgWithdrawDelegatorReward } from "cosmjs-types/cosmos/distribution/v1beta1/tx";
+import { SignMode } from "cosmjs-types/cosmos/tx/signing/v1beta1/signing";
+import { TxRaw } from "cosmjs-types/cosmos/tx/v1beta1/tx";
+import { getAccount } from "./api/Cosmos";
+import BigNumber from "bignumber.js";
 
-const buildTransaction = async (
+export const buildTransaction = async (
   account: Account,
   transaction: Transaction
 ): Promise<any> => {
@@ -163,4 +178,56 @@ const buildTransaction = async (
   return msg;
 };
 
+export const postBuildTransaction = async (
+  account: Account,
+  transaction: Transaction,
+  pubkey: any,
+  unsignedPayload: any,
+  signature: Uint8Array
+): Promise<any> => {
+  const txBodyFields: TxBodyEncodeObject = {
+    typeUrl: "/cosmos.tx.v1beta1.TxBody",
+    value: {
+      messages: unsignedPayload,
+      memo: transaction.memo || "",
+    },
+  };
+
+  const registry = new Registry([
+    ["/cosmos.staking.v1beta1.MsgDelegate", MsgDelegate],
+    ["/cosmos.staking.v1beta1.MsgUndelegate", MsgUndelegate],
+    ["/cosmos.staking.v1beta1.MsgBeginRedelegate", MsgBeginRedelegate],
+    [
+      "/cosmos.distribution.v1beta1.MsgWithdrawDelegatorReward",
+      MsgWithdrawDelegatorReward,
+    ],
+  ]);
+
+  const { sequence } = await getAccount(account.freshAddress);
+
+  const txBodyBytes = registry.encode(txBodyFields);
+
+  const authInfoBytes = makeAuthInfoBytes(
+    [{ pubkey, sequence }],
+    [
+      {
+        amount: transaction.fees?.toString() || new BigNumber(2500).toString(),
+        denom: account.currency.units[1].code,
+      },
+    ],
+    transaction.gas?.toNumber() || new BigNumber(250000).toNumber(),
+    SignMode.SIGN_MODE_LEGACY_AMINO_JSON
+  );
+
+  const txRaw = TxRaw.fromPartial({
+    bodyBytes: txBodyBytes,
+    authInfoBytes,
+    signatures: [signature],
+  });
+
+  const tx_bytes = Array.from(Uint8Array.from(TxRaw.encode(txRaw).finish()));
+
+  return tx_bytes;
+};
+
 export default buildTransaction;
diff --git a/src/families/cosmos/js-prepareTransaction.ts b/src/families/cosmos/js-prepareTransaction.ts
index 8f75721b0a..60893c56bc 100644
--- a/src/families/cosmos/js-prepareTransaction.ts
+++ b/src/families/cosmos/js-prepareTransaction.ts
@@ -1,28 +1,16 @@
 import { Account } from "../../types";
 import { Transaction } from "./types";
 import BigNumber from "bignumber.js";
-import { getAccount, simulate } from "./api/Cosmos";
-import {
-  encodePubkey,
-  makeAuthInfoBytes,
-  Registry,
-  TxBodyEncodeObject,
-} from "@cosmjs/proto-signing";
-import { SignMode } from "cosmjs-types/cosmos/tx/signing/v1beta1/signing";
-import { TxRaw } from "cosmjs-types/cosmos/tx/v1beta1/tx";
-import {
-  MsgDelegate,
-  MsgUndelegate,
-  MsgBeginRedelegate,
-} from "cosmjs-types/cosmos/staking/v1beta1/tx";
-import { MsgWithdrawDelegatorReward } from "cosmjs-types/cosmos/distribution/v1beta1/tx";
+import { simulate } from "./api/Cosmos";
+import { encodePubkey } from "@cosmjs/proto-signing";
 import { getEnv } from "../../env";
-import buildTransaction from "./js-buildTransaction";
+import { buildTransaction, postBuildTransaction } from "./js-buildTransaction";
 import { getMaxEstimatedBalance } from "./logic";
 
 const prepareTransaction = async (
   account: Account,
-  transaction: Transaction
+  transaction: Transaction,
+  calculateFees?: boolean
 ): Promise<Transaction> => {
   let memo = transaction.memo;
   let fees = transaction.fees;
@@ -32,12 +20,19 @@ const prepareTransaction = async (
   let gasQty = new BigNumber(250000);
   const gasPrice = new BigNumber(getEnv("COSMOS_GAS_PRICE"));
 
-  if (transaction.useAllAmount) {
+  if (transaction.useAllAmount && !calculateFees) {
+    const tempTransaction = await prepareTransaction(
+      account,
+      {
+        ...transaction,
+        amount: account.spendableBalance.minus(new BigNumber(2500)),
+      },
+      true
+    );
+
     amount = getMaxEstimatedBalance(
       account,
-      account.balance
-        .dividedBy(new BigNumber(getEnv("COSMOS_GAS_AMPLIFIER")))
-        .integerValue()
+      tempTransaction.fees || new BigNumber(0)
     );
   }
 
@@ -52,54 +47,19 @@ const prepareTransaction = async (
 
   // be sure payload is complete
   if (unsignedPayload) {
-    const txBodyFields: TxBodyEncodeObject = {
-      typeUrl: "/cosmos.tx.v1beta1.TxBody",
-      value: {
-        messages: unsignedPayload,
-        memo: transaction.memo || memo || "",
-      },
-    };
-
-    const registry = new Registry([
-      ["/cosmos.staking.v1beta1.MsgDelegate", MsgDelegate],
-      ["/cosmos.staking.v1beta1.MsgUndelegate", MsgUndelegate],
-      ["/cosmos.staking.v1beta1.MsgBeginRedelegate", MsgBeginRedelegate],
-      [
-        "/cosmos.distribution.v1beta1.MsgWithdrawDelegatorReward",
-        MsgWithdrawDelegatorReward,
-      ],
-    ]);
-
-    const { sequence } = await getAccount(account.freshAddress);
-
     const pubkey = encodePubkey({
       type: "tendermint/PubKeySecp256k1",
       value: Buffer.from(account.seedIdentifier, "hex").toString("base64"),
     });
 
-    const txBodyBytes = registry.encode(txBodyFields);
-
-    const authInfoBytes = makeAuthInfoBytes(
-      [{ pubkey, sequence }],
-      [
-        {
-          amount:
-            transaction.fees?.toString() || new BigNumber(2500).toString(),
-          denom: account.currency.units[1].code,
-        },
-      ],
-      transaction.gas?.toNumber() || new BigNumber(250000).toNumber(),
-      SignMode.SIGN_MODE_LEGACY_AMINO_JSON
+    const tx_bytes = await postBuildTransaction(
+      account,
+      { ...transaction, memo, fees, gas, amount },
+      pubkey,
+      unsignedPayload,
+      new Uint8Array(Buffer.from(account.seedIdentifier, "hex"))
     );
 
-    const txRaw = TxRaw.fromPartial({
-      bodyBytes: txBodyBytes,
-      authInfoBytes,
-      signatures: [new Uint8Array(Buffer.from(account.seedIdentifier, "hex"))],
-    });
-
-    const tx_bytes = Array.from(Uint8Array.from(TxRaw.encode(txRaw).finish()));
-
     const gasUsed = await simulate(tx_bytes);
 
     if (gasUsed.gt(0)) {
diff --git a/src/families/cosmos/js-signOperation.ts b/src/families/cosmos/js-signOperation.ts
index 1e138af0ee..ffd71f8804 100644
--- a/src/families/cosmos/js-signOperation.ts
+++ b/src/families/cosmos/js-signOperation.ts
@@ -8,25 +8,12 @@ import type { Transaction } from "./types";
 import { getAccount, getChainId } from "./api/Cosmos";
 import { Observable } from "rxjs";
 import { withDevice } from "../../hw/deviceAccess";
-import {
-  encodePubkey,
-  makeAuthInfoBytes,
-  Registry,
-  TxBodyEncodeObject,
-} from "@cosmjs/proto-signing";
-import { SignMode } from "cosmjs-types/cosmos/tx/signing/v1beta1/signing";
-import { TxRaw } from "cosmjs-types/cosmos/tx/v1beta1/tx";
+import { encodePubkey } from "@cosmjs/proto-signing";
 import { encodeOperationId } from "../../operation";
 import { LedgerSigner } from "@cosmjs/ledger-amino";
 import { AminoTypes } from "@cosmjs/stargate";
 import { stringToPath } from "@cosmjs/crypto";
-import buildTransaction from "./js-buildTransaction";
-import {
-  MsgDelegate,
-  MsgUndelegate,
-  MsgBeginRedelegate,
-} from "cosmjs-types/cosmos/staking/v1beta1/tx";
-import { MsgWithdrawDelegatorReward } from "cosmjs-types/cosmos/distribution/v1beta1/tx";
+import { buildTransaction, postBuildTransaction } from "./js-buildTransaction";
 import BigNumber from "bignumber.js";
 
 const aminoTypes = new AminoTypes({ prefix: "cosmos" });
@@ -51,16 +38,6 @@ const signOperation = ({
 
         const chainId = await getChainId();
 
-        const registry = new Registry([
-          ["/cosmos.staking.v1beta1.MsgDelegate", MsgDelegate],
-          ["/cosmos.staking.v1beta1.MsgUndelegate", MsgUndelegate],
-          ["/cosmos.staking.v1beta1.MsgBeginRedelegate", MsgBeginRedelegate],
-          [
-            "/cosmos.distribution.v1beta1.MsgWithdrawDelegatorReward",
-            MsgWithdrawDelegatorReward,
-          ],
-        ]);
-
         const hdPaths: any = stringToPath("m/" + account.freshAddressPath);
 
         const ledgerSigner = new LedgerSigner(transport, {
@@ -109,40 +86,15 @@ const signOperation = ({
           memo: transaction.memo || "",
         });
 
-        const txBodyFields: TxBodyEncodeObject = {
-          typeUrl: "/cosmos.tx.v1beta1.TxBody",
-          value: {
-            messages: msgs.map((msg) => aminoTypes.fromAmino(msg)),
-            memo: transaction.memo || "",
-          },
-        };
-
-        const txBodyBytes = registry.encode(txBodyFields);
-
-        const authInfoBytes = makeAuthInfoBytes(
-          [{ pubkey, sequence }],
-          [
-            {
-              amount:
-                transaction.fees?.toString() || new BigNumber(2500).toString(),
-              denom: account.currency.units[1].code,
-            },
-          ],
-          transaction.gas?.toNumber() || new BigNumber(250000).toNumber(),
-          SignMode.SIGN_MODE_LEGACY_AMINO_JSON
+        const tx_bytes = await postBuildTransaction(
+          account,
+          transaction,
+          pubkey,
+          unsignedPayload,
+          new Uint8Array(Buffer.from(signed.signature.signature, "base64"))
         );
 
-        const txRaw = TxRaw.fromPartial({
-          bodyBytes: txBodyBytes,
-          authInfoBytes,
-          signatures: [
-            new Uint8Array(Buffer.from(signed.signature.signature, "base64")),
-          ],
-        });
-
-        const signature = Buffer.from(TxRaw.encode(txRaw).finish()).toString(
-          "hex"
-        );
+        const signature = Buffer.from(tx_bytes).toString("hex");
 
         if (cancelled) {
           return;