A freelancer's first invoice almost always has something wrong: a missing field, a number that breaks the sequence, or a forgotten withholding. It is not a disaster —it can be corrected— but an incomplete invoice can stop your client from deducting the expense, and leave you exposed if the tax agency reviews your books. This guide covers what an invoice must contain, which taxes belong on it and when the simplified version is enough.
Which fields are mandatory
Spanish invoicing rules set a minimum content. A full (or "ordinary") invoice includes:
- Number and series. Sequential, with no gaps within each series.
- Issue date and, if different, the date of the transaction.
- Your details and your client's: name or company name, tax ID (NIF) and full address for both.
- Description of the transaction: what you did or delivered, with quantity and unit price.
- Taxable base, VAT rate applied and VAT amount, itemised.
- Income tax withholding, where applicable, and the total payable.
- If the transaction is exempt or under the reverse charge, the wording that justifies it.
Numbering: sequential, no gaps
Invoices are numbered sequentially within each series. You can run several series (one per year, or one for corrective invoices), but within each one no number may be missing or repeated. The cleanest common pattern is 2026001, 2026002, and so on. Never delete an issued invoice to reuse its number: if there is a mistake, you issue a corrective invoice, which leaves the right trail in your books and in that period's VAT.
Which VAT rate applies
Spain has several rates. These are the current reference rates (always check the one that applies to your activity and tax year):
| Rate | % | Typical cases |
|---|---|---|
| Standard | 21 % | Most professional services and goods |
| Reduced | 10 % | Hospitality, passenger transport, some building work |
| Super-reduced | 4 % | Bread, milk, books, medicines |
| Exempt | 0 % | Regulated education, healthcare and other listed cases |
If you invoice a client in another EU country with a valid VAT number, the transaction usually carries no VAT under the reverse charge, with the corresponding wording on the invoice. To work out bases and amounts without fighting the decimals, use the VAT calculator.
When to apply income tax withholding
Withholding is not optional and does not depend on preference: it depends on who your client is. If you are a professional (an activity in the second section of the Spanish business tax classification) and you invoice a company, another freelancer or an entity, the invoice carries withholding. If you invoice a private individual, it does not.
The general reference rate is 15 %, with a reduced 7 % during the year of registration and the two following years for new professionals. Check the rate in force for your case. Your client pays the withholding to the tax agency on your behalf: that is why what you collect is less than base + VAT. You do not lose it — it is subtracted later in your form 130 instalment and in the annual return.
Example on a €1,000 base: VAT at 21 % = €210, withholding at 15 % = €150. You invoice €1,210 but collect €1,060. Of that, €210 is VAT that is not yours: you will settle it in form 303.
Simplified vs. full invoice
A simplified invoice (the old "receipt") can be issued for small amounts —up to €400 as a general rule, and up to €3,000 in certain sectors such as hospitality or transport, both reference figures— and does not require the customer's identifying details. The catch that matters: if your client wants to deduct the expense, they need a full invoice with their tax ID. When in doubt, issue the full one.
Common mistakes
- Skipping numbers or reusing a cancelled one instead of issuing a corrective invoice.
- Forgetting withholding when invoicing companies as a professional.
- Spending the VAT collected: it is not income, it is the tax agency's money in transit.
- Issuing a receipt to a company that needs to deduct the expense.
- Not keeping copies of invoices issued and received (they must be kept for years).
