Correcting an invoice you have already printed
What you can fix after printing, what needs a fresh invoice, and how to handle it properly.
Last updated: 25/09/2026
If the customer has not taken the printed invoice away, the simplest thing is to correct it and print another, then void the wrong one. Do not let two sheets share the same invoice number outside your control.
If the customer has already taken it away, do not quietly change the figures in your system. An invoice is a document both sides hold; change one side and the other no longer matches.
The cleanest route is to issue a correcting invoice stating the original invoice number, what is being corrected, and the difference. The original stays as it is and is never torn up.
If the difference is small and both sides agree to leave it, note internally which amount was waived. If someone asks later, you still have something to answer with.
For an invoice already sent to a business customer, tell them before issuing the correcting invoice. The buyer usually needs paperwork that matches their own books, and an unannounced document easily puts the two sets out of step.
The point to remember: invoice numbers are never reused. Once a number is printed, it belongs to the sheet of paper someone is holding, not to the software.