Burofax: Spain's Certified Demand Letter and When to Send One (2026)

Spanish law keeps attaching consequences to one question: can you PROVE what you told someone, and when? A burofax is the everyday tool built to answer yes. Correos certifies the content of the message, the delivery and the date, which turns a letter into evidence, and in several situations the law rewards exactly that kind of provable notice. This page covers what a burofax is, when it changes a legal outcome, and how to send one properly.

Information last verified on 23 July 2026. This page provides general legal information about Spanish law and does not constitute legal advice in an individual case.

What exactly gets certified

The Correos burofax service certifies three things an ordinary letter cannot prove:

• The content. Correos certifies the text you sent («certificación de contenido»), with legal value as proof against third parties, and you can request that certification up to five years after the sending, extendable custody up to 120 months.
• The delivery and its date. The delivery is recorded under the recipient's signature, and the acuse de recibo documents who received it, and when.
• Your own copy. The sender can keep a certified copy of the communication.

Delivery is fast: same day for shipments admitted before 13:00 to areas with special delivery units, next working day otherwise. You can send from any Correos office or entirely online, and the headline price starts at 12,72 €, rising with page count and options.

That combination is what Spanish practice calls a medio fehaciente: a way of communicating that reliably proves content, delivery and date. A burofax is the common vehicle; a notarial requerimiento achieves the same thing at higher cost. An ordinary certified letter (carta certificada) proves that SOMETHING was delivered, but not what it said, which is why it fails where the content matters.

Where the law rewards a fehaciente notice

Before an eviction. The clearest verified example: in a desahucio for unpaid rent, the tenant can normally stop the case once by paying everything owed. But art. 22.4 LEC removes that right when the landlord demanded payment by a fehaciente means at least 30 days before filing and was not paid by the filing date. One burofax, sent early, changes the endgame of the whole eviction procedure.

Ending or not renewing a tenancy. The LAU runs on notice windows: the tenant's 30-day notice against the annual extensions, and the four-month (landlord) and two-month (tenant) notices around the end of the five-to-seven-year period (arts. 9 y 10 LAU). A burofax proves the notice existed and when it arrived, which is the entire dispute in most non-renewal fights.

Claiming a debt. The escalation ladder for reclaiming money starts with a documented demand: it fixes the claim, interrupts prescription as an extrajudicial demand (art. 1973 CC), and builds the paper base for a later monitorio. Creditors also use it as the requerimiento previo de pago warning of possible inclusion in a delinquency file, which data-protection rules require before ASNEF listing.

Everything contractual. Terminating services, claiming against builders or insurers, community-of-owners disputes, employment communications: whenever a deadline, a termination or a warning may later be denied, the burofax is the cheap way to make denial impossible.

How to write one that works

The certification covers what you wrote, so write it like the evidence it will become:

• Identify everyone: your full details, the recipient's, and the contract or relationship concerned.
• State the facts and the demand precisely: the amount owed and its origin, or the notice being given, with dates. Vague prose certifies vagueness.
• Set a deadline and the consequence: payment within X days, or the announced next step (claim, termination, ASNEF communication, desahucio).
• Keep it factual and civil. Threats or insults in a certified document are certified threats and insults; they can even ground an injurias claim.

Send it with acuse de recibo and request the content certification. If the recipient refuses it or cannot be found, the attempt itself is recorded, and Spanish case law has generally treated a refused fehaciente communication as effective notice, since the recipient cannot benefit from refusing to receive it.

This page is general legal information about Spanish law and does not constitute legal advice in an individual case. The controlling texts are the current versions in the BOE and the conditions published by Correos.

Frequently Asked Questions

What is a burofax and what does it prove?

It is a certified communication sent through Correos that proves three things an ordinary letter cannot: the exact content of the message, the fact of delivery under the recipient's signature, and the date. The content certification can be requested up to five years after sending, and the whole package has evidentiary value against third parties.

How much does a burofax cost?

Correos' published price starts at 12,72 € and rises with the number of pages and the options chosen, like the acuse de recibo and the content certification. It can be sent from any Correos office or online, with delivery the same day or the next working day in normal cases.

Is a burofax legally required before suing?

Usually not required, but often decisive. In tenancy, a fehaciente payment demand sent at least 30 days before an eviction claim removes the tenant's right to stop the case by paying late (art. 22.4 LEC). In debt claims it fixes the amount and date and serves as the prior warning the law demands before some steps, like listing a debtor in ASNEF.

What happens if the recipient refuses the burofax?

The refusal or the failed delivery attempt is itself documented. Spanish case law has generally treated a communication the recipient refused as effective notice, because nobody can benefit from refusing to receive what was properly sent to them; the certified attempt becomes your evidence.

Is a burofax the same as a certified letter?

No. A carta certificada proves that a delivery happened, but not what the envelope contained. The burofax certifies the content itself, plus delivery and date, which is what courts need when the dispute is about what was communicated. A notarial requerimiento achieves the same at higher cost.