A handwritten invoice is legal in Spain as long as it includes all mandatory fields set by Royal Decree 1619/2012. From 1 July 2027 autónomos must issue invoices through VeriFactu-certified software, but until then a carefully written paper invoice meets AEAT requirements. This guide covers what to write, in what order, how to number correctly, and when to switch to a digital tool. For the full autónomo tax context, see the autónomo guide.
Quick answers
Is a handwritten invoice legal in Spain? Yes, until 1 July 2027 for autónomos. Content matters, not format.
Mandatory fields: invoice number, issue date, your NIF and address, client NIF and address, service description, taxable base, VAT rate and amount, IRPF withholding if applicable, and total due.
After issuing: keep a copy for 6 years, log it in your VAT book, and declare it on Modelo 303.
Deadline to switch: companies by 1 July 2026, autónomos by 1 July 2027 (Royal Decree 15/2025). After that, VeriFactu-certified software is mandatory.
Before you start
Gather these six items before putting pen to paper. Missing any of them means starting over:
Your full legal name or trading name, NIF/NIE, and registered address. This must match what AEAT has on file.
Your client's full name or company name, NIF or CIF, and registered address. Ask for it before the job starts, not after.
Your next invoice number. Check your VAT book for the last number issued and add one. Never skip or reuse numbers.
The issue date. For B2B invoices this is typically the date the service was completed or the goods delivered.
A clear description of the service or goods. Vague entries like "professional services" increase audit risk. Be specific.
The agreed price before tax. This is your taxable base (base imponible). Confirm it matches your quote or contract.
How to write the invoice: step by step
Write "FACTURA" and the invoice number at the top. Example: FACTURA Nº 2026-001. The number must continue from your previous invoice without gaps. If you use a series letter, include it: 2026-A-001.
Add the issue date. Write the full date in DD/MM/YYYY format. Example: 10/05/2026.
Write your supplier details. Full legal name or trading name, NIF, and registered address. This is your information as the person or business issuing the invoice.
Write the client details. Full name or company name, NIF or CIF, and registered address. For B2B invoices this is mandatory. For retail sales under €400 where the buyer does not need to deduct VAT, a simplified invoice without the client NIF is permitted.
Describe the service or goods. Be specific. Instead of "services," write "Graphic design for autumn 2026 campaign, 15 hours at €60/hour." The clearer the description, the lower the audit risk.
Write the taxable base (base imponible). This is the net amount before tax. Example: €900.00.
Apply the correct IVA rate and calculate the VAT amount. Standard rate is 21%. Reduced rate is 10% for food, hospitality, and transport. Super-reduced rate is 4% for basic foods, books, and medicines. Write the rate and the amount separately. Example: IVA 21% = €189.00.
Apply IRPF withholding if applicable. If your client is a Spanish registered business or professional and you are an autónomo providing professional services, deduct IRPF. Standard rate is 15% (7% in your first three years of activity). Write it as a negative line. Example: IRPF 15% = -€135.00.
Calculate and write the total due. Taxable base + VAT - IRPF = total. Example: €900 + €189 - €135 = €954.00. Write this clearly at the bottom.
Sign the invoice, add your payment details, and make a copy before handing it over. Include your IBAN for bank transfer and a payment due date. Photograph or photocopy the original before giving it to the client.
After you issue the invoice
Keep a copy for 6 years. Spanish law requires a 4-year retention period (the AEAT limitation period). Six years is best practice to cover any extension of inspection periods.
Log it in your VAT book (libro de facturas emitidas). Record the invoice number, date, client name, taxable base, VAT amount, and IRPF amount. This book is what AEAT checks first during an inspection.
Declare it on Modelo 303. The taxable base and VAT amount from this invoice go into your quarterly VAT return. Modelo 303 is due within 20 days of the end of each quarter (April, July, October, January).
If IRPF was withheld, confirm the client will submit Modelo 111. The client pays the withheld IRPF to AEAT on your behalf via Modelo 111. You receive the reduced amount and do not pay that IRPF yourself.
If unpaid after the due date, send a reminder. You are entitled to late payment interest (ECB rate + 8 percentage points) and a €40 fixed recovery fee under Ley 3/2004, without any prior warning.
Common mistakes to avoid
Skipping the client NIF on a B2B invoice. Without the client's NIF, the invoice is not a valid full invoice (factura completa). The client cannot deduct input VAT and will ask you to reissue it.
Applying the wrong VAT rate. Using 21% when 10% applies (or vice versa) means your client over- or under-deducts, and AEAT will flag the discrepancy. Confirm the rate for your specific activity before writing.
Forgetting the IRPF line on B2B professional invoices. If you bill another Spanish business for professional services and omit IRPF, the client will withhold it anyway when paying. The invoice will not match the payment.
Gaps or restarts in invoice numbering. A gap (jumping from 005 to 007) triggers AEAT scrutiny. Restarting the series mid-year (going back to 001 in July) is not permitted.
Editing an invoice after issuing it. Once the client has the invoice, the original is fixed. To correct an error, issue a factura rectificativa referencing the original number. Never cross out and rewrite on the original.
Vague service descriptions. "Consulting" or "professional services" without further detail increases inspection risk. Write what you did, for whom, and at what rate.
Not keeping a copy. If the client loses the invoice, you must be able to issue a duplicate. Without a copy, you cannot reconstruct your VAT book accurately.
When handwritten invoices stop working
Three situations make handwritten invoices impractical or legally invalid:
You invoice regularly and volume is growing. Maintaining sequential numbering, a handwritten VAT book, and quarterly Modelo 303 calculations manually becomes error-prone above a handful of invoices per month. One transposition error in a VAT calculation means a corrected tax return.
Your client is a public body. Ministries, councils, hospitals, and any state agency require invoices in Facturae 3.2.1 or 3.2.2 XML format delivered via the FACe portal. Handwritten or PDF invoices are not accepted. This is current law with no grace period.
From 1 July 2027 for autónomos (1 July 2026 for companies). Royal Decree 15/2025 makes VeriFactu-certified software mandatory for all invoicing. Each invoice must carry a cryptographic hash and QR code. Handwritten invoices will not meet the legal requirement regardless of their content.
For a comparison of free invoicing apps that handle all of this automatically, see best free invoicing apps.
FAQ
Is a handwritten invoice legally valid in Spain? Yes, provided it includes all fields required by Royal Decree 1619/2012: invoice number, dates, both parties NIF and address, description, tax base, VAT rate and amount, IRPF if applicable, and total. Format (handwritten, typed, or software-generated) is not the deciding factor - content is.
Can I write an invoice on plain paper? Yes. There is no requirement for special paper, letterhead, or a stamp. A plain A4 sheet with all mandatory fields is compliant. That said, a professional layout improves payment speed in practice.
What if I made a mistake after handing the invoice to the client? Issue a factura rectificativa. Write it on a new document, reference the original invoice number and date, state what was wrong, and show the corrected amounts. The rectificativa is what AEAT expects - never alter the original.
Do I need to charge IRPF on every invoice? No. IRPF withholding applies only when the client is a Spanish registered business or professional. Individual consumers and non-resident foreign clients do not withhold IRPF. When in doubt, ask the client before issuing.
When must I switch to certified software? Companies (S.L., S.A., and other Corporate Tax payers) must switch to VeriFactu-certified software by 1 July 2026. Autónomos and sole traders must switch by 1 July 2027. Both deadlines are set by Royal Decree 15/2025. Choose a compliant platform now rather than migrating in a rush. Full detail at VeriFactu guide.
Bottom line
A handwritten invoice is legal today as long as it includes every mandatory field. Write your NIF and address, the client NIF and address, a sequential invoice number, the tax base, the correct VAT rate and amount, IRPF withholding if applicable, and the total. Keep a copy for six years, log it in your VAT book, and declare it on Modelo 303. From 1 July 2027 autónomos must move to VeriFactu-certified software - start with renn now so the transition is a non-event. For autónomo registration and quarterly compliance, renn handles setup end to end.
