3 files changed, 19 insertions, 11 deletions
diff --git a/packages/instant/src/containers/selected_erc20_asset_amount_input.ts b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
index 1fc5b6d8c..325dc0ef2 100644
--- a/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
+++ b/packages/instant/src/containers/selected_erc20_asset_amount_input.ts
@@ -82,7 +82,7 @@ const updateBuyQuoteAsync = async (
 
     // set error if user doesn't have appropriate balance
     const takerAddress = await getBestAddress();
-    await balanceUtil.checkSufficientBalanceAndFlashError(takerAddress, newBuyQuote, web3Wrapper, dispatch);
+    await balanceUtil.checkInsufficientEthBalanceAndFlashError(takerAddress, newBuyQuote, web3Wrapper, dispatch);
 };
 
 const debouncedUpdateBuyQuoteAsync = _.debounce(updateBuyQuoteAsync, 200, { trailing: true });
diff --git a/packages/instant/src/util/address.ts b/packages/instant/src/util/address.ts
index 97ed30a00..14d42d8c0 100644
--- a/packages/instant/src/util/address.ts
+++ b/packages/instant/src/util/address.ts
@@ -1,6 +1,6 @@
 import { web3Wrapper } from '../util/web3_wrapper';
 
-export const getBestAddress = async (): Promise<string> => {
+export const getBestAddress = async (): Promise<string | undefined> => {
     const addresses = await web3Wrapper.getAvailableAddressesAsync();
     return addresses[0];
 };
diff --git a/packages/instant/src/util/balance.ts b/packages/instant/src/util/balance.ts
index d442da9e0..954dc7156 100644
--- a/packages/instant/src/util/balance.ts
+++ b/packages/instant/src/util/balance.ts
@@ -1,30 +1,38 @@
 import { BuyQuote } from '@0x/asset-buyer';
 import { Web3Wrapper } from '@0x/web3-wrapper';
+import * as _ from 'lodash';
 import { Dispatch } from 'redux';
 
 import { ZeroExInstantError } from '../types';
 
 import { errorUtil } from './error';
 
+const hasSufficientFunds = async (takerAddress: string | undefined, buyQuote: BuyQuote, web3Wrapper: Web3Wrapper) => {
+    if (_.isUndefined(takerAddress)) {
+        return false;
+    }
+    const balanceWei = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+    return balanceWei >= buyQuote.worstCaseQuoteInfo.totalEthAmount;
+};
+
 export const balanceUtil = {
     /**
      * Checks to see if user has enough balance to buy assets
      * If they do not, flash an error and return false
      * If they do, return true
      */
-    checkSufficientBalanceAndFlashError: async (
-        takerAddress: string,
+    checkInsufficientEthBalanceAndFlashError: async (
+        takerAddress: string | undefined,
         buyQuote: BuyQuote,
         web3Wrapper: Web3Wrapper,
         dispatch: Dispatch,
     ) => {
-        const balanceWei = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
-
-        if (balanceWei < buyQuote.worstCaseQuoteInfo.totalEthAmount) {
-            const balanceError = new Error(ZeroExInstantError.InsufficientBalance);
-            errorUtil.errorFlasher.flashNewError(dispatch, balanceError);
-            return false;
+        const hasEnoughFunds = await hasSufficientFunds(takerAddress, buyQuote, web3Wrapper);
+        if (hasEnoughFunds) {
+            return true;
         }
-        return true;
+        const balanceError = new Error(ZeroExInstantError.InsufficientBalance);
+        errorUtil.errorFlasher.flashNewError(dispatch, balanceError);
+        return false;
     },
 };