Guide updated 11 July 2026
What an invoice must contain
An invoice that lacks a mandatory data point may not be valid for deducting VAT and is the first to go unpaid. This is what article 6 of the Invoicing Regulation requires, in the order it asks for it.
The mandatory data
a) Number and, if there are any, series, in sequence. b) Date of issue. c) Name and surname or company name of the issuer and the recipient. d) Tax ID (NIF) of the issuer and, when it is a company or professional, of the recipient. e) Address of both. f) Description of the transactions. g) VAT rate applied. h) VAT amount. i) Date of the transaction if different from the date of issue. j) If the transaction is exempt or reverse charge applies, the mention and the article that justifies it (RD 1619/2012, art. 6).
What is not mandatory but gets you paid
The due date and the payment account are not required by the Regulation, but without them the invoice is paid late: Ley 3/2004 gives 30 days if there is no date, and an invoice without an IBAN forces the customer to ask. Including them speeds up collection more than any reminder.
The simplified invoice
Up to €400 (VAT included), or €3,000 for retail sales and other cases in art. 4, a simplified invoice is enough: number, date, NIF and name of the issuer, description, VAT rate or «VAT included» and total.
From 2027, the QR code
With Verifactu (RDL 15/2025: 1 January 2027 for companies and 1 July for the rest), every invoice will also carry a QR code with NIF, number, date and amount, which the customer can check with the tax authority.
Frequently asked questions
Is the customer's NIF always mandatory?
When the customer is a company or professional, yes. For a private individual, only in some cases (for example, if they ask for it to exercise a tax right).
Can I correct an invoice that has already been sent?
It is not modified: a corrective invoice is issued that refers to the original (RD 1619/2012, art. 15).