# Correcting invoices

Invoices <model-account.invoice> can only be changed when they are in a draft state.

Once an invoice has been posted you will need to credit it <Crediting customers and suppliers>, and reissue it by creating a new invoice with the correct information on.

Tip

If you need to create a new invoice that is almost the same as an existing invoice you can use the Duplicate item from the form’s menu to copy the existing invoice. The duplicate invoice will be created in a draft state, so you can change anything that was incorrect.

# Cancelling invoices

Most Invoices <model-account.invoice> can be cancelled up to the point they are paid. Once they are paid you need to credit them instead. You do this by creating a credit note <Crediting customers and suppliers> for them.

Note

Legislation may not allow you to cancel a posted customer invoice. If this is the case, then you should instead create a credit note for it.

You can allow posted invoices to be credited by changing the setting in your Company <company:model-company.company>.

Cancelling an invoice removes its effect on your accounts by either removing its Account Move <account:model-account.move>, or negating it with a cancelling move.

# Crediting customers and suppliers

In Tryton you credit customers and suppliers by creating Credit Notes. These are just Invoices <model-account.invoice> with negative totals. You can create a credit note manually or create one based on an existing invoice.

To credit existing invoices you must first select the invoices that need to be credited. Next you run the Credit <wizard-account.invoice.credit> invoice wizard from the Launch action menu.