Locking Sales Transactions
How to protect sales documents from a closed period against modification.
After closing an accounting period, you can protect older sales records from modification. Go to Settings → Finance → General Settings, enter the lock date, and select the document types.
You can separately select invoices, pro forma invoices, credit notes, and payments. Both selections are required: the date and at least one document type.
Before enabling this feature, verify that all outstanding payments and credit notes have been entered. Also, consider any bank or accounting imports that might attempt to add documents to the past period.
The period lock operates independently of permissions to edit documents after dispatch or finalization. If a record falls within the locked period, these permissions alone are insufficient.