Bookkeeping

Cancelling an invoice: why you should never just delete it

An invoice sent by mistake or to the wrong customer should be cancelled, not deleted. What cancelling (voiding) means, when to cancel and when to issue a credit note instead, what to tell the customer, and what changes once it has been paid or reported for tax.

9 Nov 2026 · 6 min read

The wrong invoice is cancelled, not removed. It keeps its number in the list, and the replacement takes the next one.

Jonah does the accounts for a small joinery in Norwich. He copies last month's invoice to Saltmarsh Ltd to save time, forgets to change the quantity, and sends £2,640 instead of £1,320. The client spots it within the hour. His first thought is to delete the invoice and send a new one with the same number. That would leave the client holding a document that, as far as his records are concerned, never existed. The clean fix takes two minutes: cancel it and issue the right one.

Why not delete it

The customer has it. Once sent, it may already be in their accounts system. Your records should say what happened to it.
Your numbers need to run without gaps. In many countries invoice numbers must be in an unbroken sequence. A deleted invoice is a gap you cannot explain; a cancelled one is a gap with a reason. See how to number invoices.
Reusing the number causes confusion. Two different documents with the same number is worse than a gap.
An auditor or tax inspector looks for exactly this: invoices that disappear.

A draft is different. Nobody else has seen it, so change it or delete it freely. The rule applies from the moment an invoice is issued.

What cancelling means

Cancelling, often called voiding, keeps the invoice and its number but marks it as having no effect. It no longer counts as a sale, it is not owed, and it should not appear in your sales or tax totals. The record stays, with the date and ideally the reason, so anyone looking later can see what happened.

Cancel, or issue a credit note?

Situation	Fix
Not issued or sent yet	Edit it, or delete the draft
Sent, wrong from the start, nothing paid	Cancel it, then issue a correct one
Sent twice by mistake	Cancel the duplicate
Right at the time, but the amount must come down	A credit note
Already paid, in full or in part	A credit note, and a refund if money goes back
Already in a tax return you have filed	Usually a credit note in the current period; check with your accountant

Cancel when the invoice should never have existed in that form: the wrong customer, the wrong amount throughout, a duplicate. Use a credit note when the sale happened but the amount owed changed afterwards, or when money has already moved. Our guide on fixing a wrong invoice with a credit note covers credit notes in detail.

Once a payment is recorded

An invoice that has been paid, even in part, cannot simply be cancelled, because the payment has to belong to something. Either take the excess back with a credit note and refund it, or keep it as credit for the next invoice. See also refunding a paid invoice.

Once it is in a tax return

If you have already reported the invoice in a VAT or GST return, cancelling it now would change a period that is closed. Many tax systems expect a credit note dated now, which reduces your tax in the current period. In India, for example, an invoice already reported in GSTR-1 is usually corrected with a credit note, and a government e-invoice (IRN) can only be cancelled within a short window. Rules differ, so check with your accountant before cancelling anything from a past period.

Tell the customer

Send a short note as soon as you cancel, so they do not pay the wrong one:

“Hi Lucy, invoice OG/2026/0048 had the wrong quantity, so I have cancelled it. Please ignore it. The correct invoice is OG/2026/0049 for £1,320.00, attached. Sorry for the confusion.”

Name both numbers. If they have already entered the wrong one, they need to know which to remove. If they have already paid it, stop and use a credit note instead.

Keep the reason

Write down why each invoice was cancelled: a note on the invoice, or a line in your records. “Wrong quantity, replaced by 0049.” A year later, when your accountant asks about the gap, the answer is there.

In Openn InvoiceA draft has no number yet, so Delete draft leaves no gap. An issued invoice cannot be edited. Open it and choose Cancel invoice, then tap again to confirm. It keeps its number and stays in your list marked Cancelled, and your customer's link to it says it was cancelled by your business. Cancelling works only while no payment is recorded on the invoice, and any credit note against it has to be cancelled first. Choose Duplicate on the cancelled invoice for a new draft with the same details, correct it and issue it with the next number. In India, an invoice with an IRN also needs its IRN cancelled on the e-invoice portal, which allows that within 24 hours of generating it. With your own API access to the portal connected in Settings, Openn Invoice can cancel it for you.

The short version

Never delete or reuse the number of an invoice once it has been issued.
Cancel an invoice that should never have existed in that form, then issue a correct one.
Use a credit note when the sale happened but the amount changed, or money has moved.
If the invoice is in a filed tax return, ask your accountant before cancelling.
Tell the customer both numbers: which one to ignore and which replaces it.