The specified Tax 'GST on Income' cannot be applied to Revenue Account

This error can occur when either the Rounding and Adjustment Item accounts are mismatched, or where the GL mapping from the Setup Tables in ConnectWise are incorrectly allocated to the Account (Revenue Account) or the COGS (Direct Cost of Sales) when the item is being created.

In this example the word GST on Income is in reference to a Xero Tax Type. This could also apply for any of the tax codes as listed on the Xero Tax Codes table in Wise-Sync > Companies Setup tabs..

Solution 1: Account Mismatch on Xero Rounding and Adjustment Items

Information you'll need..

1. The ConnectWise Account & COGS account numbers & the Revenue & Direct Cost accounts from Xero

Steps to take

1.1 The account code contained in the Rounding and Adjustment Items in Wise-Sync Company Setup, may be mismatched with the wrong tax type for the applicable type of sale (Sale / Purchase). You will need to check the Account code in the Wise-Sync Company Setup > Rounding & Adjustment Tabs.


Input Form Field
Account / Tax Type
Item Sales AccountRevenue Account
Item Sales TaxSales Tax
Item Purchase AccountDirect Cost / Expense Account
Item Purchase TaxPurchase Tax (or Exempt)


Solution 2: Account Mismatch on Sync of Items

Information you'll need..

1. The ConnectWise Account & COGS account numbers & the Revenue & Direct Cost accounts from Xero

Steps to take

1.1 The account code contained in the Item Line which caused the error may have the wrong type for the applicable tax type. You will need to check the Account code in the ConnectWise Setup Tables under GL Accounts




In the above example, account 400 is a Revenue Account in Xero. Therefore only valid "Revenue Tax Types" can be used for this account type, and when the tax type "GST on Expenses" or another "Purchases Tax" is being applied to the item, the error is returned.




1.2 You will need to update the account in the GL Accounts mappings, so that it uses a valid "Purchases" account.

In Xero go into the Chart of Accounts

1.3 The Revenue Account needs to have matching Cost of Sales accounts. Search for the account code that you got out of ConnectWise in Xero, it should have GST on Expenses or another corresponding Tax Rate (Name).


1.4  Now you will need to check the COGS code in the ConnectWise Setup Tables under GL Accounts. The Expense (COGS) Account needs to have matching Expense accounts. Search for the COGS account code in Xero, it should have GST on Expense or OUTPUT. Repeat steps 1.1 & 1.2 for the COGS account


1.5 Ensure all changes have been saved.

2.1 Re-sync to Xero