What Is a Credit Note? How to Issue One and When You Need To

What Is a Credit Note?

A credit note (also called a credit memo) is a document issued by a seller to reduce the amount owed on an invoice. It's essentially the opposite of an invoice: where an invoice says "you owe me X," a credit note says "I owe you Y" (or "you now owe me X minus Y").

Credit notes are used to correct invoicing errors, process returns, or acknowledge that a service wasn't fully delivered.

When Do You Need to Issue a Credit Note?

1. Goods Were Returned

The most common reason. A client bought 20 units but returns 5. Rather than cancelling the original invoice and reissuing it, you issue a credit note for the value of the 5 returned items.

2. You Overcharged

You accidentally invoiced for 10 hours when the actual work was 8. Issue a credit note for the 2-hour difference.

3. Goods Were Damaged or Defective

The client received damaged items and you've agreed to a partial refund or price reduction. A credit note formalises that agreement.

4. Agreed Discount After the Fact

You offered a discount after the invoice was already issued — perhaps as a goodwill gesture for a long-term client. A credit note records the adjustment.

5. Service Not Delivered in Full

A project didn't fully complete as specified, and you've agreed to reduce the invoice accordingly.

6. Cancellation Before Payment

If the client hasn't paid yet and you need to cancel the invoice entirely, a full credit note (for the total invoice amount) is cleaner than just voiding the invoice — it creates an auditable record.

Why Not Just Cancel the Invoice?

In proper accounting, you shouldn't delete or modify invoices once issued. Invoices are numbered sequentially and should create a complete, unbroken record. "Fixing" an invoice by editing it after the fact makes your records unreliable.

Instead, the invoice stays as-is in your records, and the credit note creates a corresponding entry that adjusts the net balance. Your accounts show both the original charge and the correction — which is cleaner for auditing and tax purposes.

What Should a Credit Note Contain?

The words "Credit Note" clearly displayed

A unique credit note number

The date issued

Reference to the original invoice number it relates to

Your business name and contact details

The client's name and address

Itemised description of what's being credited (matching the original invoice line items)

The amount being credited (and applicable tax)

Total credit amount

How Does a Credit Note Affect Accounting?

When you issue a credit note:

Your accounts receivable decreases (you're owed less)

If GST/VAT was charged on the original invoice, the credit note reverses the corresponding tax amount

For the client, their accounts payable decreases

In cash terms: if the client has already paid the full invoice, the credit note creates a liability on your side — you either refund the amount or apply it as a credit against their next invoice.

Credit Note vs Refund

A credit note and a refund are related but different:

Credit note: A paper/electronic document recording that the client is owed a reduction. May or may not result in a cash payment.

Refund: The actual transfer of money back to the client.

You can have a credit note with no refund (applied against the next invoice instead). You can have a refund without a credit note (though this is poor practice — you should always document the adjustment).

Best Practices

Issue credit notes promptly. If a return or overcharge has been agreed, document it immediately. Delays create confusion about what's still owed.

Reference the original invoice. Every credit note should clearly reference the invoice it adjusts. Without this link, reconciliation becomes a puzzle.

Get client acknowledgement. For significant amounts, confirm that the client has received and accepted the credit note. This prevents disputes later.

Keep sequential numbering. Credit notes, like invoices, should be numbered sequentially for a complete audit trail.