diff --git a/modules/abstract-utxo/src/abstractUtxoCoin.ts b/modules/abstract-utxo/src/abstractUtxoCoin.ts
index 639cffe546..4d8312abdf 100644
--- a/modules/abstract-utxo/src/abstractUtxoCoin.ts
+++ b/modules/abstract-utxo/src/abstractUtxoCoin.ts
@@ -4,7 +4,7 @@ import { randomBytes } from 'crypto';
 import _ from 'lodash';
 import * as utxolib from '@bitgo/utxo-lib';
 import { bip32 } from '@bitgo/secp256k1';
-import { bitgo, getMainnet, isMainnet } from '@bitgo/utxo-lib';
+import { bitgo, getMainnet } from '@bitgo/utxo-lib';
 import {
   AddressCoinSpecific,
   BaseCoin,
@@ -1001,22 +1001,7 @@ export abstract class AbstractUtxoCoin
       return requestedFormat;
     }
 
-    if (isTestnetCoin(this.name)) {
-      return 'psbt-lite';
-    }
-
-    const walletFlagMusigKp = wallet.flag('musigKp') === 'true';
-    const isHotWallet = wallet.type() === 'hot';
-
-    // Determine if we should default to psbt format
-    const shouldDefaultToPsbt =
-      wallet.subType() === 'distributedCustody' ||
-      // if mainnet, only default to psbt for btc hot wallets
-      (isMainnet(this.network) && getMainnet(this.network) === utxolib.networks.bitcoin && isHotWallet) ||
-      // default to psbt if it has the wallet flag
-      walletFlagMusigKp;
-
-    return shouldDefaultToPsbt ? 'psbt' : undefined;
+    return 'psbt-lite';
   }
 
   async getExtraPrebuildParams(buildParams: ExtraPrebuildParamsOptions & { wallet: Wallet }): Promise<{
diff --git a/modules/abstract-utxo/test/unit/txFormat.ts b/modules/abstract-utxo/test/unit/txFormat.ts
index 57bbe60459..fdef9ba0b6 100644
--- a/modules/abstract-utxo/test/unit/txFormat.ts
+++ b/modules/abstract-utxo/test/unit/txFormat.ts
@@ -3,7 +3,7 @@ import * as assert from 'assert';
 import { Wallet } from '@bitgo/sdk-core';
 
 import { AbstractUtxoCoin, ErrorDeprecatedTxFormat, TxFormat } from '../../src';
-import { getMainnetCoinName, isMainnetCoin, isTestnetCoin } from '../../src/names';
+import { isMainnetCoin, isTestnetCoin } from '../../src/names';
 
 import { utxoCoins, defaultBitGo } from './util';
 
@@ -110,42 +110,11 @@ describe('txFormat', function () {
       expectedTxFormat: 'psbt-lite',
     });
 
-    // DistributedCustody wallets default to PSBT (mainnet only, testnet already covered)
+    // All mainnet wallets default to psbt-lite
     runTest({
-      description: 'should return psbt for distributedCustody wallets on mainnet',
+      description: 'should return psbt-lite for all mainnet wallets',
       coinFilter: (coin) => isMainnetCoin(coin.name),
-      walletFilter: (w) => w.options.subType === 'distributedCustody',
-      expectedTxFormat: 'psbt',
-    });
-
-    // MuSig2 wallets default to PSBT (mainnet only, testnet already covered)
-    runTest({
-      description: 'should return psbt for wallets with musigKp flag on mainnet',
-      coinFilter: (coin) => isMainnetCoin(coin.name),
-      walletFilter: (w) => Boolean(w.options.walletFlags?.some((f) => f.name === 'musigKp' && f.value === 'true')),
-      expectedTxFormat: 'psbt',
-    });
-
-    // Mainnet Bitcoin hot wallets default to PSBT
-    runTest({
-      description: 'should return psbt for mainnet bitcoin hot wallets',
-      coinFilter: (coin) => isMainnetCoin(coin.name) && getMainnetCoinName(coin.name) === 'btc',
-      walletFilter: (w) => w.options.type === 'hot',
-      expectedTxFormat: 'psbt',
-    });
-
-    // Other mainnet wallets do NOT default to PSBT
-    runTest({
-      description: 'should return undefined for other mainnet wallets',
-      coinFilter: (coin) => isMainnetCoin(coin.name),
-      walletFilter: (w) => {
-        const isHotBitcoin = w.options.type === 'hot'; // This will be bitcoin hot wallets
-        const isDistributedCustody = w.options.subType === 'distributedCustody';
-        const hasMusigKpFlag = Boolean(w.options.walletFlags?.some((f) => f.name === 'musigKp' && f.value === 'true'));
-        // Only test "other" wallets - exclude the special cases
-        return !isHotBitcoin && !isDistributedCustody && !hasMusigKpFlag;
-      },
-      expectedTxFormat: undefined,
+      expectedTxFormat: 'psbt-lite',
     });
 
     // Test explicitly requested formats