You can always correct a link afterwards, for example if an automatic rule has put an invoice on the wrong expense item. Find the invoice among the linked invoices in Invoice, or in the Invoice tab on the production code, and change or remove the link.
Via the Invoice module
Go to Invoice → Incoming invoice.
Choose the quick selection for linked invoices at the top.
Find the invoice, for example using the search field.
Open the link, and choose a new place or remove the link.
Via the production code
Go to Prod. codes and open the production code.
Select the Invoice tab. There you see all invoices on the code.
Open the invoice and change the link.
Good to know
Automatic rules, such as invoice import on an expense item in Setup and Operation, can place invoices incorrectly if another cost is coded to the same code. In that case, correct the link for the invoices concerned.
If the production code on the invoice is wrong, it must be corrected in the accounting system or on the invoice in AIMZ.