How can I change the invoice number?

In order to ensure that an invoice can be assigned, invoice numbers should only be changed with care.

Why invoice numbers?

The invoice number is the number that can only be assigned to one document without any doubt. If several documents are given the same number, the two can no longer be separated from one another.

Automatic invoice numbers in Billomat

For this reason, Billomat only distributes provisional invoice numbers for all invoices in the draft status. It works like this:

  1. For example, the last completed invoice has the number RE-123456 .
  2. All  invoices in draft status are now given the provisional invoice number  RE-123457 , which only becomes valid when an invoice is closed.
  3. All other invoices that have not been completed are then automatically incremented .

Enter and change the invoice number manually

When creating an invoice, provided that this has not yet been completed, the invoice number can be entered manually.

However, caution is advised here, as the consecutive invoice number is  endangered. Billomat then continues to count from the manually entered number.


If you enter the invoice number RE-654321 , the next automatic number is no longer  RE-123458 .

In theory, invoice numbers can be assigned twice, but should not. Billomat therefore always warns against two numbers should be the same.

If the invoice has already been closed, it is no longer possible to change it with Billomat. Of course, this also applies to the invoice number. At this point, a correction calculation should be made instead.