Does the recipient of a certified SMS need to install anything?

No: they receive an ordinary SMS on any phone, with no apps or sign-ups. Certification happens on the provider's platform.

What is the difference between a certified SMS and a burofax?

Both provide reliable proof of a communication. The certified SMS is delivered in seconds to the phone, costs a fraction, supports bulk sending and its certificate is verifiable online by third parties for 10 years.

Does a certified SMS prove delivery?

Yes: the delivery confirmation returned by the mobile network is recorded with date and time in the sealed certificate.

9 credits per sending · from €0.26

Certified SMS: the burofax now fits in a text message

You write a text message and we put everything else on record: what it said, when it left and when it was delivered. In seconds, your communication becomes a sealed certificate with evidential force — no paper, no waiting, and nothing for the recipient to install.

Send my first certified SMS See pricing

Reaches any mobile phone
10-year custody included
Verifiable by third parties

SMS · Sender: YOUR COMPANY We remind you that contract no. 4482 expires on 30/09. You may renew it at your branch before that date.

CERT-2026-081437CERTIFIED SMS

Evidence Record

Content recorded 156 characters · digital fingerprint computed
Sent to the recipient 2026-08-30 10:32:05 · +34 6•• ••• ••1
Delivered to the handset network confirmation · 4 seconds later
Certificate sealed Mensatek + FNMT · 10-year custody

SHA-256 9f1c…e7a2 · verifiable at /csvsms/

Trust Service Provider
supervised in Spain Double seal
Mensatek + FNMT on every certificate ISO 27001 & ISO 9001
independently audited 10-year custody
at no extra cost Spanish engineering
operating since 1998

How it works

You write; the proof builds itself

Write and send

From the dashboard (one by one or thousands from a spreadsheet) or from your application via API. With your own sender name and, if you like, scheduled for later.

We record every event

The exact content, the moment of sending and the network's delivery confirmation are logged and sealed with timestamps, with no human intervention.

You receive the certificate

A PDF sealed by two qualified trust service providers (Mensatek and the FNMT), kept in custody for 10 years and verifiable online by any third party.

What gets proven

What every certificate contains

The content, letter by letter
The full text of the SMS with its cryptographic fingerprint: if anything changed afterwards, verification would fail.
Certain date and time
Every event carries a timestamp, the time reference with a legal presumption of accuracy.
Sending and delivery
The destination number and the delivery confirmation returned by the mobile network, with its exact instant.
The double seal
Certificates are sealed by two qualified trust service providers: Mensatek and the FNMT.

Notification certificateSEALED PDF

Reference: CERT-2026-081437
Sender: Your Company Ltd
Destination: +34 6•• ••• ••1
Content: “We remind you that contract no. 4482 expires on 30/09…”
Sent: 2026-08-30 10:32:05 CET
Delivered: 2026-08-30 10:32:09 CET
Seals: ✓ Mensatek · ✓ FNMT
Custody: 10 years · public CSV verification

Why SMS

The channel nobody leaves unread

SMS needs no apps, no data plan, and no membership of anything: it works on every mobile phone in the world.

Delivered in seconds

If the phone is on, the notification arrives instantly; if not, it is delivered as soon as it regains coverage.

Painless bulk sending

Upload a spreadsheet with thousands of recipients and personalise the text with their data. Each sending produces its own certificate.

API for your systems

Trigger certified notifications from your ERP, CRM or application with one REST call and receive statuses on your webhook.

10-year custody

You don't have to keep anything safe: the certificate stays in custody, available in your account for a decade at no extra cost.

Public verification

Any third party — a court, the other side, an expert witness — can check the certificate with its CSV code, without asking you for anything.

A fraction of the burofax

From €0.26 per notification against roughly €23 for a burofax — with no trips to the post office and no opening hours.

Real cases

Where it makes the difference

Debt

Payment demands

Prove the prior out-of-court demand and its date before escalating the case.

Contracts

Expiry and non-renewal notices

Notices served within the deadline, with proof of when they were sent.

Employee communications

Summonses, changes of conditions or notices that require a reliable record.

Property

Meeting calls and levies

Convene owners' meetings and notify resolutions with a certified receipt for each owner.

Insurance & banking

Regulatory requirements

Communications required by regulation, with evidence ready for the supervisor.

Appointments

High-value appointments

Confirmations with evidential force to reduce no-shows and support penalties.

What legal validity does it have?

The certificate is an electronic document, signed and sealed with timestamps, admissible as evidence under the European eIDAS Regulation (EU 910/2014) — which forbids denying legal effect to an electronic document merely for being electronic — and under the Spanish Civil Procedure Act. Unlike a screenshot or your own internal logs, here the record is made by an impartial third party: a supervised Trust Service Provider, with the evidence also sealed by the FNMT.

An honest nuance others skip

A certified notification proves the sending, the content and the delivery — it does not force the recipient to read it, just as a burofax does not force anyone to collect it. The practical difference is that a text message is almost always read, almost immediately, and you keep the proof of everything, date included, for whatever you need to argue later.

Frequently asked questions

About certified SMS

How much does a certified SMS cost?

9 credits per sending of up to 160 characters (+3 credits per additional part). Depending on the pack, a credit costs €0.029 to €0.043: between €0.26 and €0.39 per certified SMS. All the figures are on the pricing page.

Does the recipient have to do or install anything?

No, nothing. They receive an ordinary SMS on any phone, with no apps and no sign-ups. The certification happens on our platform, not on their handset.

How does it differ from a burofax?

The purpose is the same: communicating with reliable proof. The medium changes: the certified SMS is delivered in seconds to the phone (no pick-up required), costs a fraction, can be sent to thousands of recipients at once, and its certificate is verifiable online by third parties for 10 years.

Will I know whether the message was delivered?

Yes: the delivery confirmation returned by the mobile network is recorded with its date and time in the certificate, and you can follow each sending from the dashboard or via webhook in your application.

Can I use my own name as the sender?

Yes, sendings go out with your account's sender name so the recipient knows who is writing — which also improves read rates.

Combine it with the rest of the platform

One account, one credit balance and one API for the whole platform.

Next time you need a burofax, you won't

Create your account in a minute and send your first certified SMS today. Prefer a walkthrough first? +34 910 606 161.

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