Invoice Correction Checklist

Before you start

Once an invoice has been sent to a customer, you cannot simply edit or delete it and pretend the original never existed — the customer may already have it in their records, and quietly changing or removing it breaks the audit trail on both sides. The right approach depends on what is wrong and whether the invoice has been paid, but it always preserves a clear record of the original, the correction and the reason.

Before you fix anything, identify exactly what is wrong, confirm whether the customer has paid, and check whether GST is affected. This is general guidance, not tax advice — confirm any GST correction with the ATO or your accountant. For the wider context, see how to correct a mistake on an invoice.

Work out what kind of fix you need

Match the correction to the problem:

• A minor detail not yet sent for payment may simply be re-issued before the customer acts on it
• A wrong amount on an unpaid invoice usually needs a credit note and a corrected invoice
• An overcharge already paid usually needs a credit note and a refund or future credit
• A wrong customer or entity needs the invoice reversed and re-issued correctly
• A GST error needs care — confirm the correct treatment before adjusting

Deciding the approach first stops you from making a quick edit that creates a bigger reconciliation problem.

Make the correction cleanly

Whichever route applies, keep the trail intact:

1. Do not delete the original issued invoice
2. Use a credit note to reverse or reduce it where it has gone out
3. Issue a corrected invoice with its own number, referencing the original
4. State clearly what changed and why
5. Adjust GST consistently with the original
6. Update your ledger so the balance is right

The test is whether someone reading your records later can follow exactly what happened — original, correction and reason all visible.

Tell the customer

A correction the customer does not understand causes confusion:

• Explain the change to the same billing contact
• Send both the credit note and the corrected invoice where used
• Confirm the new amount due and the due date
• If they overpaid, agree whether it is refunded or credited
• Keep the correspondence with the documents

Being upfront about a mistake and showing exactly how you have fixed it usually preserves the relationship better than a silent re-send.

Common mistakes

Corrections go wrong in these ways:

• Deleting the original — destroying the audit trail
• Silent edit — changing figures without telling the customer
• No cross-reference — a corrected invoice that does not name the original
• Reusing the number — giving the corrected invoice the old number

Use credit notes and clear cross-references to keep corrections clean. This works hand in hand with your credit-note and numbering practices. Our free invoice tools help you keep a consistent layout across the original and the correction. This is general information only — confirm GST corrections with the ATO or your accountant.