Basically, our understanding is as follows:

• When Bills (effects) are generated, the system uses the accounts defined in the corresponding setup (red box), which is working correctly.
• When invoices are posted, the system uses the accounts defined in the Factoring section (blue box) only when the Factoring option is applied, which is also correct.

However:

• When the Factoring option is not used, the system is posting to a 431 account (Bills Account) as if the document were a bill.
• From an accounting perspective, we believe it should instead post to a 430 account (Customer / Receivables Account), since the document is an invoice and not a bill.

Impact

This behavior causes that, during settlement and posting processes:

• Balances remain in the Bills accounts (431)
• Even though no actual bills have been managed

Conclusion / Requirement

In simple terms, we believe there is a missing configuration option.

• There should be an additional field/column in the Customer Posting Group setup to define which account to use when:
• The document type is an Invoice
• And Factoring is not applied

This would ensure that a 430 account is used instead of a 431 account, aligning the system behavior with the expected accounting treatment. We are experiencing this issue across all our clients in Microsoft Dynamics 365 Business Central SaaS.