You can save an invoice as a draft, preview it, and make as many edits as you need. However, once an invoice is finalised, you won’t be able to edit it. If you spot a mistake on a finalised invoice, you’ll have to create a new one. You can do this easily by duplicating the original invoice as a new draft, making the edits you need, and finalising again. You can manually amend the invoice number to avoid things being out of sync. You can then delete the original invoice.