Sales Credit Notes: Keeping Invoice Corrections and Refunds Clear

A customer sends back part of an order, or you spot that an invoice went out at the wrong price. What’s the right way to put it right? For most businesses, the answer is a sales credit note: a document that reduces or cancels an invoice you’ve already issued, while leaving the original in place so anyone can see what changed and why.

Credit notes sound simple, but they’re easy to muddle with refunds, discounts, and unpaid debts. This guide covers how to keep each correction clear for your records, your customer, and your accountant. VAT and accounting treatment depend on your circumstances, so speak to us for advice tailored to your situation.

What a credit note is for

A credit note records a genuine reduction in the amount a customer owes you. Common reasons include goods returned, a service cancelled or cut short, an agreed discount that wasn’t applied, a pricing mistake, or an invoice sent twice. In each case something about the sale has actually changed.

What it isn’t for is making an awkward balance disappear. If a customer hasn’t paid and you haven’t agreed any reduction, the invoice still stands. Issuing a credit note just to tidy up an overdue list hides a debt that may still be recoverable, and it gives a misleading picture of your sales.

Start every credit note with a clear reason. A note such as “Two chairs returned from invoice 1042, return accepted 6 October” (an illustrative wording) tells your bookkeeper exactly what happened. “Adjustment” or “customer unhappy” tells them almost nothing.

Leave the original invoice alone

Once an invoice has gone to a customer, resist the temptation to edit or delete it. Change the original and you lose the record of what the customer was actually charged. Your accountant then sees a figure with no history, and your customer may be holding a version that no longer matches yours.

The better approach is to keep the invoice exactly as issued and raise a credit note that refers to it by number and date. Most accounting software will link the two for you and let you allocate the credit against the original invoice. Our bookkeeping service can help you set up a routine so corrections are recorded the same way every time.

If only part of an invoice is being credited, say which part. Name the items or services affected and the quantities, so the remaining balance makes sense without anyone digging through old email threads.

Credit notes and refunds

A credit note changes what’s owed. A refund moves money. They often happen together, but they answer different questions, and recording one doesn’t complete the other. What happens after a credit note depends on where the invoice stands:

1. Unpaid invoice. The credit reduces the balance the customer still owes, and no money needs to move.
2. Partly paid invoice. The credit reduces what’s left, and may clear the remaining balance or leave the customer in credit.
3. Fully paid invoice. The customer now has a credit balance with you, to be refunded or used against a future invoice, as agreed.

Here’s an illustrative example with made-up figures for a VAT-registered business charging VAT at the standard rate of 20%. You invoice a customer for ten items at £50 each: £500 plus £100 VAT, a total of £600. The customer returns two items and you agree to credit them. The credit note is for £100 plus £20 VAT, a total of £120. If the invoice is unpaid, the customer now owes £480 (£400 plus £80 VAT). If they’d already paid the £600, they have a £120 credit balance to be refunded or set against their next invoice.

When a refund is made, record it against the same customer and link it to the credit note. If it goes back through a card provider, keep the provider’s reference too. That way nobody refunds the same amount twice through different routes, and the customer’s account ends up at zero for the right reason.

VAT details to get right

If you’re VAT registered, the credit note needs to reflect the VAT charged on the original sale, not a figure worked out backwards from whatever you’re refunding. HMRC’s VAT Notice 700 covers credit notes as part of its guidance on adjusting VAT when the price of a supply changes. It sets out the details a VAT credit note should show, such as its own number and date, your details and the customer’s, the reason for the credit, a description of what’s being credited, the VAT rate, and the amounts including the VAT credited. It also deals with when the adjustment belongs in your VAT return.

Keep the dates straight. The original sale date, the date the change was agreed, the credit note date, and any refund date can all be different. Don’t backdate a credit note to land it in the same month as the sale or to make a report balance.

HMRC’s guide to keeping VAT records includes credit and debit notes among the records you need to keep. If a VAT return covering the original sale has already been submitted, mention that when you ask for advice, as the right approach can depend on whether it’s a later agreed change or a correction of an earlier mistake.

If you’re not VAT registered, your credit notes shouldn’t show VAT at all. They should still carry a number, a date, a reason, and a reference to the original invoice.

Who approves a credit note

Even a small business benefits from a simple rule about who can issue credits. Decide who approves a credit note, who creates it, and who confirms any refund. For a sole trader that may all be you, but a short record of the reason and the approval still helps at year end.

Before sending a credit note, check it against the evidence: the right customer, the right invoice reference, the right items, and the right amounts. A credit posted to the wrong customer leaves two accounts wrong at once.

Tell the customer clearly what’s changed. Say which invoice the credit relates to, what they now owe or are owed, and what happens next. Avoid promising a refund date until whoever handles payments has confirmed it.

Month-end checks on credits

Most businesses check unpaid invoices every month. Fewer check credit balances. At month end, list any customer credits that haven’t yet been refunded or used. Some will be waiting for a refund, some for the customer’s next order, and some may turn out to be duplicates.

A short review list works well: customer, original invoice, credit note number, reason, date, and next step. Keep card details and other sensitive payment information out of it.

Watch the pattern as well. A run of credits for the same product or the same kind of billing mistake usually has a cause you can fix. If you follow your trading through monthly figures, our article on reading your management accounts explains why sales and the cash behind them can tell different stories.

Credits that are never followed up tend to surface at the year end, when they’re harder to explain. Our piece on the hidden risks of poor bookkeeping looks at how small gaps like these build up.

Questions about sales credit notes

Is a credit note the same as writing off a bad debt?

No. A credit note reflects an agreed reduction in the sale. A bad debt is money that’s still owed but that you don’t expect to collect. They’re recorded differently, and VAT-registered businesses have separate rules for relief on bad debts. Talk to your accountant before writing anything off.

Can I just edit an invoice if I spot a mistake?

If the invoice hasn’t gone to the customer yet, simply correct it before it’s sent. If it has, it’s usually clearer to issue a credit note and, where needed, a corrected invoice. Editing a sent invoice leaves you and your customer holding different versions of the same document.

Can a credit be used against a different invoice?

Yes, if you and the customer agree. Record the allocation in your software so the credit is clearly linked to the invoice it’s settling, and let the customer know. Don’t mark another invoice as paid separately without showing where the credit went.

What about a credit note a supplier sends us?

That’s a purchase credit note, and it belongs with your purchase records. Match it to the supplier invoice it relates to and check whether you’re expecting a refund or a lower balance to pay. Keep it separate from the credits you issue to your own customers.

Should a credit note include the customer’s card details?

No. Use invoice, customer, and transaction references instead, and process any card refund through your payment provider’s secure system. Never ask a customer to email their full card number so you can complete the paperwork.