Nota de Crédito
Credit Note
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A certified fiscal document that corrects or partially reverses a previously issued invoice. Required in Portugal because invoices cannot be edited or deleted once issued.
In Portugal, once you issue an invoice, it's permanent. No edits, no deletions. The tax authority (AT) has a record of it the moment it's created. If something is wrong, you overcharged a client, applied the wrong VAT rate, or need to cancel the transaction entirely, the only legal path is a Nota de Crédito.
How it works
A Nota de Crédito (NC) is a certified fiscal document that references an original invoice and reverses all or part of it. It must include:
- The number and date of the original invoice
- The amount being corrected (partial or full)
- The reason for the correction
The NC is issued through the same certified invoicing software you use for your faturas. It gets its own sequential number in the NC series and is signed and reported to the AT, just like any other document in the chain.
The effect depends on the original document
What happens after you issue an NC depends on the type of invoice it corrects:
- FT (fatura): The original invoice created a payment obligation. The NC reduces or eliminates that obligation. If the client hasn't paid yet, they now owe less (or nothing).
- FR/FS (fatura-recibo / fatura simplificada): These documents confirm payment already happened. An NC against them creates a refund obligation, you owe the client money back.
In both cases, the NC reduces your reported VAT for the period. If you're on the normal VAT regime, this directly lowers what you owe in your next VAT return.
Correction reason is mandatory
You can't issue a blank NC. Portuguese law requires a stated reason, whether it's a pricing error, a service cancellation, a return, or a duplicate invoice. The reason is part of the certified document and visible to the tax authority.
This isn't bureaucracy for its own sake. The document chain tells a complete story: invoice issued, correction made, reason recorded. Every NC is traceable back to the original invoice it corrects.
Frequently asked questions
O que é uma Nota de Crédito?
A Nota de Crédito (NC) is a fiscal document that corrects a previously issued invoice. Since invoices in Portugal can never be deleted or modified after issuance, the NC is the only legal way to reverse an overcharge, account for a returned product, or fix a billing error.
When do I need to issue a Nota de Crédito?
You issue an NC when you need to correct an invoice you already issued, for example, you charged the wrong amount, the client returned goods, you applied the wrong VAT rate, or you need to cancel the invoice entirely. The NC references the original invoice and states the reason for the correction.
Can I just delete an invoice instead of issuing a Nota de Crédito?
No. Portuguese law requires all certified documents to be permanent. Once an invoice is issued, it exists in the system forever, sequentially numbered and reported to the tax authority. The only way to correct it is by issuing an NC that references the original.
Does a Nota de Crédito affect my VAT?
Yes. An NC reduces the VAT you owe for the period in which it's issued. If you charged 23% VAT on a 1,000 euro invoice and then issue a full NC, the 230 euros of VAT is reversed. The tax authority sees both documents and calculates the net liability.
How is a Nota de Crédito numbered?
Like all certified documents in Portugal, an NC gets a sequential number within its own series (NC series). It's part of the same signed document chain as your invoices, issued through certified software and reported to the AT.
Related terms
The English name for Nota de Crédito, a document that reverses or corrects a previously issued invoice when it can't be deleted or modified.
FaturaInvoiceA formal invoice issued through certified software or the AT portal. For solo entrepreneurs on the simplified regime, income tax and Social Security remain cash-basis (tied to payment) regardless of when the invoice is issued.