How to Correct, Cancel or Void an Invoice

Everyone sends a wrong invoice eventually: wrong amount, wrong client, wrong tax, a duplicate. The fix is straightforward once you know the rule: once an invoice has been sent, don't edit it. Issue a new document that corrects it.

Step 1: Has it been sent?

Not sent yet: fix it. Edit the draft, check it, then send. If your numbering is sequential and you've already used the number for this draft, keep using it; nothing external has seen it.

Sent: don't change it. The client may already have entered it into their system, and your records need to show what was actually issued. Use one of the approaches below.

Common situations and fixes

Problem	Fix
Amount too high	Issue a credit note for the difference
Amount too low	Issue a supplementary invoice for the difference (or credit the whole thing and reissue)
Wrong client	Credit note for the full amount; new invoice to the right client
Duplicate invoice sent	Credit note for the duplicate, and tell the client which to pay
Wrong tax (VAT/GST/sales tax)	Credit note for the full invoice; reissue correctly
Typo in address or description	Often a corrected copy is accepted, clearly marked; for VAT invoices, use a credit note and reissue
Work cancelled after invoicing	Credit note for the full amount
Client paid, then returned goods	Credit note, then refund or hold as credit

Credit notes

A credit note is the standard way to reduce or cancel an invoice. It has its own number (CN-0005), references the original invoice, and shows the amount (and tax) being reversed. See what is a credit note.

In the generator, choose Credit note as the document type, enter the original invoice number in the reference field, and list what you're crediting.

Credit and reissue

For anything more than a simple reduction, the cleanest method is:

1. Issue a credit note for the full original invoice
2. Issue a new invoice, with a new number, that's correct
3. Tell the client: "Please disregard INV-0181, which has been cancelled by credit note CN-0005. The correct invoice is INV-0184, attached."

It's two extra documents, but anyone looking at your records later can see exactly what happened.

What about "void"?

Accounting software often lets you void an invoice. That's appropriate when an invoice was created in error and never sent. Voiding keeps the number in the system (so there's no gap) but marks it as having no effect. If the invoice was sent to the client, a credit note is better practice, and for VAT-registered businesses it's usually required.

If you use this site, invoices are just files you create, so "voiding" means making a note in your invoice log that the number was not used or was cancelled, and why.

What never to do

• Don't reuse an invoice number for a different invoice.
• Don't delete a sent invoice from your records.
• Don't send a changed invoice with the same number as though nothing happened, especially if VAT or sales tax is involved.
• Don't quietly adjust the next invoice to "make up" for an error without documenting it.

Tell the client, briefly

Hi Sam, I made an error on INV-0181: the day rate should have been $950, not $1,050. I've attached credit note CN-0005 cancelling it and a corrected invoice, INV-0184, for $4,750. Sorry for the confusion.

Short, factual, and one apology is plenty.

Preventing the next one

A 30-second check before sending catches most errors: client name, amount, tax rate, dates, PO number. There's a fuller list in common invoicing mistakes.