Fix a mistake on an invoice you already finalized

Can I change an invoice after finalizing it?

Yes — open the invoice and choose Amend. You can fix the items, the price, the date or the customer, and the invoice keeps its number. Behind the scenes nothing is overwritten: Dukaaan reverses the original accounting entry, posts the corrected one, and puts the before-and-after in your activity log. The PDF shows the amendment date.

Some situations stop an amendment, on purpose: a payment recorded against the invoice must be reversed first, the amended total cannot drop below credit notes already issued against it, and once a period's GSTR-1 has been pushed or filed the invoice is locked — corrections for a filed period go through GSTR-1A in your next filing, so talk to your CA.

The short answer

A credit note still works, and is often what your CA prefers when the customer already has the original: it reverses what was wrong — the whole invoice, or just the incorrect lines — while both documents stay on record. Cancelling is for an invoice that should never have existed: it keeps its number (that is what keeps your GST filings clean), the entry is reversed, the stock comes back, and it shows as Cancelled everywhere.

Why it works this way

A finalized invoice is a legal document. Your customer has a copy, it may be in a GST return, and your books balance around it. Software that lets you quietly overwrite last month's invoice is software whose numbers nobody can rely on — including you.

So every correction leaves a trail instead of overwriting. Anyone looking at the account later sees the original figures, the reversal, and the corrected entry, in order — whether the fix was an amendment, a credit note or a cancellation.

Cancelling instead

If the invoice should never have existed at all, cancel it and record why. Cancelling reverses the accounting entries but keeps the numbered document, because a gap in your invoice numbers is a question you do not want to answer at filing time.

There is no un-cancel. If you cancel one by mistake, raise a fresh invoice — do not go looking for a way to reverse the cancellation.

If it is still a draft

None of this applies. A draft has not become anything yet: edit it freely, or delete it outright.