Hi there, @R_Crane.
I'd be pleased to help share information about the Out of Scope Agency Payable account.
The Out of Scope Agency Payable account is one of the default accounts created by QuickBooks Online (QBO) and use for sales tax recording. Any transaction which is selected as taxable, but has $0.00 tax amount it will be posted to the Out of Scope Agency Payable Liability account.
Since you're using AvaTax to calculate sales tax via QBO, the amount of taxes calculated is added to the Sales Tax Payable Liability account. QBO calculate $0.00 amount that is posted to the Out of Scope Agency Payable Liability account.
In addition, the account can't be deleted since it's a default account in QuickBooks.
To learn more about sales tax in QBO, you may check this article: Sales tax in QuickBooks Online.
Don't hesitate to add a post/comment below if you have any other sales tax concerns. I'll be always here to help you!
