Hi John,
Are you working on a US or Canada tenant install? Are you wanting to use Sales Tax? Or are you wanting to use VAT?
If you want Sales Tax, (and not VAT), then be sure the 'VAT Bus. Posting Group' is blank on Customers, Vendors, or/and GL Accounts. That field is strictly for VAT tax.
The error message you receive suggests it has DEFAULT in perhaps the Customer card....which it then in turn requires the Tax Posting Setup to need that combination of what the error suggests. But the issue is you should not have the DEFAULT in the VAT Bus. Posting Group. Again, that is VAT only.
Also, within GL Setup, you should have 'VAT in Use' = NO.
US and CA use Tax Areas with Jurisdictions, Tax Groups and Tax Details.
You should have 1 line within the Tax Posting Setup which is "Blank", "Blank", Sales Tax....just like the 1st line Franziska shows in her screenshot.
Thank you.
Bryan
