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The notice that reaches any phone and holds up as proof.

An SMS gets opened in seconds — no apps, no internet, nothing for the recipient to do. With lofirmo, it is also captured in an evidence report: what was said, to whom, when it was delivered, and the exact content.

  • No internet or apps on the recipient's end
  • PDF evidence report
  • One-off, bulk or via API
Trust Service Provider Qualified Timestamping ISO 27001 & ISO 9001 Human support · +34 910 606 161
Why SMS

When it has to reach them, no matter what

It doesn't depend on them checking their inbox or having an app installed: the SMS pops up on the screen of any phone, from the newest smartphone to the most basic handset.

Universal reach

It reaches any mobile number in the world over the carriers' networks, with no requirements on the handset.

Report with the full text

The report captures the complete message, the sender, the recipient and every status change, word for word.

Delivery confirmation

We record the delivery confirmation issued by the carrier network when the message reaches the handset.

Qualified proof of date

Every milestone is fixed with a qualified timestamp: the exact moment of sending and delivery is beyond dispute.

Bulk sending

Upload your contact list and notify hundreds or thousands of recipients at once, with an individual evidence report for each one.

API and automation

Send certified SMS straight from your ERP or CRM and receive every status change via webhook.

Use cases

The instant alternative to burofax

Everything you send today by burofax (the Spanish registered-letter service) or certified mail can go out in seconds, at a fraction of the cost, evidence included.

  • Debt collectionPayment demands with proof of content and delivery, ready to back a claim in court.
  • Expirations and renewalsContract-end notices, lock-in periods and automatic renewals, all served within the deadline.
  • Changes in termsCommunicate changes to rates or clauses and prove they were notified on time.
  • Summons and meeting noticesHomeowners' association meetings, assemblies and formal appointments with proof the notice went out.
  • Workplace communicationsFormal notices to your workforce whenever you need certified proof on record.
  • Incidents and claimsReport incidents to insurers or suppliers within the contractual deadline.
How it works

From message to report in three steps

Write the message

From the web platform or from your own software via API. Enter the recipient or upload a list for bulk sending.

We certify it

We send the SMS, track its delivery through the carrier network and record every milestone with a timestamp.

Download the report

You receive the PDF evidence report with the full text, the recipient, the statuses and the cryptographic hash.

Frequently asked questions

Common questions about Certified SMS

How does a Certified SMS hold up against a burofax? +

Both are notification channels backed by evidence. The practical difference: a Certified SMS arrives in seconds, no one has to go and collect it, and it costs a fraction. The report, issued by a trusted third party and sealed with qualified proof of date, certifies content, sending and delivery, and can be submitted in court or administrative proceedings.

What if the recipient's phone is switched off? +

The carrier network retries delivery for hours until the handset becomes available again. The report faithfully reflects the sequence: when the message was sent and when it was delivered — or the final status if delivery never took place.

Does the recipient see anything different from a regular SMS? +

They receive an SMS like any other, in their usual message inbox. The certification happens in our infrastructure: they don't need to install anything, sign up or confirm anything for the evidence to be generated.

Can I send thousands of certified SMS at once? +

Yes. You can upload a file with your recipients and personalize the text with variables (name, amount, date…). Each recipient generates their own individual evidence report, and via API you can automate the entire process from your systems.

Free account · no card required

Your next important notice, on the record

Create your free account and send your first Certified SMS today with your trial credit.

Prefer to talk it through? +34 910 606 161 · Monday to Friday