Hi Courtny,

please go to posting control window and query for the control type PP38 and control type AC7 and check whether there is an account assigned for the posting type if yes please go into the account and  check the validity period of the account and code part demands of the account.

Best regards,
Kanishka

Hi,

looking at the screenshots I assume you would like to offset an advance payment. When a advance payment is posted usually a tax code needs to be applied which is coming from the advance invoice or manually applied when no connection to an order exists. For the paid amount tax is calculated and posted..

When matching the advance payment against the final invoice the tax posting will be reversed, because the tax from the final invoice will be posted.

The error message states that no account can be found for posting in PP36. AC7 is the control type for tax code.

The tax code used in the payment is not in the details of PP36. Please check which tax code “sits” on the payment and add the combinartion tax code/account to the the posting control type PP36 in the details. 
Using a default value might work in scenarios where you only have one account for all used tax codes. But the you can use the control type AC1 with a fixed account.

The default value will be used for all tax codes that are not defined in the details of the posting control.
This might lead to incorrect posting for tax.

Regards

Ralph