What is a credit note?

What is a credit note, and why issue one

A credit note is a document from a seller to a buyer that reduces the amount owed on an earlier invoice, in part or in full. It is the correct way to fix an invoice that has already been sent. Instead of editing or deleting the original, you issue a credit note that points to it and shows the change.

Common reasons to issue one:

• The customer returned goods, or some goods arrived damaged.
• You overcharged: a wrong quantity, price or tax rate.
• You agreed a discount or allowance after the invoice went out.
• The whole invoice was raised in error, or the job was cancelled.

Ireland’s Revenue says a VAT credit note is required when the original price changes because of an allowance, discount or similar adjustment, or when the VAT rate on the original invoice was wrong.

Credit note vs debit note vs refund

A credit note lowers what the buyer owes. A debit note usually raises it, or in some systems is the buyer’s own request for a credit. A refund is the actual money going back to the buyer. A credit note can lead to a refund, but it can also simply be offset against the next invoice.

The debit note column shows why the term confuses people. HMRC’s VAT Notice 700 treats a valid debit note as reflecting a mistake, an undercharge or an agreed increase in the value of a supply. Ireland’s Revenue describes a debit note issued by a customer to their supplier that can be treated as a credit note, as long as the supplier accepts it and it is issued before the supplier’s own credit note.

Credit note vs credit memo

They are the same document under two names. “Credit note” is the usual term in the UK, Ireland, Australia, New Zealand and much of Asia. “Credit memo”, short for credit memorandum, is more common in the United States. Both reduce an invoiced amount and should reference the original invoice.

Pick the term your customers expect and stick with it. A US client’s accounts team will recognize “credit memo”, while a UK client will look for “credit note”. The content is the same either way.

How to reference the original invoice

Quote the original invoice number and its date on the credit note, ideally near the top and again on each credited line. HMRC lists the number and date of the original VAT invoice among the details a valid credit note must show, and Ireland’s Revenue requires a cross reference to the original invoice. This is what links the correction to the sale.

Clear wording looks like this:

• CN-2026-0007 dated 21 October 2026, “Credit against invoice INV-2026-0142 dated 12 October 2026”.
• For a partial credit, name the line: “Line 2, 80 units returned as misprinted”.
• For several invoices, list each number and date, then the amount credited against each.

HMRC adds that if you cannot link the credit to a particular invoice, for example with returned goods that cannot be matched, you must be able to satisfy HMRC by other means that you accounted for VAT on the original supply. Give credit notes their own series; see invoice numbering for formats.

What a credit note should show

A credit note mirrors an invoice, with the amounts reversed and a link back to the original. At minimum, show its own number and date, both parties’ details, the original invoice reference, what is being credited, the amount, and the tax rate and amount credited if tax applied. Adding the reason helps the buyer’s accounts team process it.

How a credit note affects tax

In general, a credit note reduces the tax on the original sale. The seller’s output tax falls by the tax credited, and a registered buyer reduces the tax they claimed by the same amount. The credit should use the tax rate that applied to the original invoice, which Ireland’s Revenue states directly.

HMRC adds a point worth knowing: if a credit note is issued without a VAT adjustment, it should say “This is not a credit note for VAT”. Even then, both parties still need to adjust their records of sales and purchases to complete their VAT returns.

Rules on timing and which return the adjustment goes in vary by country, so check your tax office’s guidance or ask an accountant if the credit is large or crosses a tax period.

Worked example: a partial credit with 15% GST

A made up New Zealand printer, Kowhai Print Co, invoices 500 brochures at $1.40 each plus 15% GST. The customer reports 80 misprinted brochures, and the printer credits them. The credit note reverses 80 units and their GST, leaving the customer owing for 420 units. All figures below are worked to the cent.

If the customer had not paid yet, they now pay $676.20. If they had paid $805.00, the printer either refunds $128.80 or holds it as credit against the next order, as the two agree. Prices are examples only.

Why you should not edit or delete a sent invoice

Once an invoice has gone to a customer, treat it as fixed. Editing it means your copy and theirs no longer match, and deleting it leaves a gap in your numbering. A credit note keeps a clear trail: the original stays, the correction sits beside it, and anyone checking later can see what changed and why.

To cancel an invoice completely, issue a credit note for the full amount, then raise a fresh invoice if the sale still goes ahead. Our credit note generator lets you enter the original invoice number and date, and the invoice maker handles the replacement. If the issue was the agreed payment window rather than the amount, read payment terms explained instead.