Currently, when the field ‘Confirmations, delivery and invoicing on hold’ = ‘Tax Invoice’ is set on the Customer Master, sales order invoices are blocked from processing, while other transaction types such as Customer Free Text Invoices and Customer Payment Journals are allowed to process under certain conditions.

For example:

• A credit Free Text Invoice processes successfully, but a debit Free Text Invoice fails.
• A credit Customer Payment Journal processes successfully, but a debit Payment Journal fails.

This behavior makes sense as it prevents increasing the customer’s balance while allowing reductions.

However, credit Sales Order Invoices, which also reduce the customer’s balance, are currently blocked from processing. 

Suggestion: Sales Order Invoices—especially credit transactions—should be allowed to process when they reduce the customer’s balance, just like the other transaction types. This would ensure consistency across invoice and payment processing logic and reduce manual workarounds.