Expert witness service

Messaging and email

We analyse whether a WhatsApp or Telegram conversation, or an email, is authentic and unaltered: extraction from the device or mailbox, metadata, hash values and chain of custody. The Spanish Supreme Court ruling STS 116/2025 (Criminal Chamber, 13 February 2025) holds that an expert report is not needed in every case, but that when the evidence is challenged with reasons it is normally the expert report that proves its authenticity, so this report matters most when the evidence is challenged, or is expected to be. From €450 + VAT (€544.50 incl. VAT) per conversation or thread.

From: €450 + VAT (€544.50 incl. VAT)
Turnaround: 10 working days

Free initial consultation See fees

When you need it

The other side challenges the screenshots of a WhatsApp or Telegram conversation you submit.
A labour or commercial dispute depends on emails whose authorship or date is contested.
A conversation is suspected of having been edited, trimmed or fabricated.
You want to strengthen a key piece of evidence before it is challenged.

What we deliver

An expert report in line with UNE 197001:2019, checked with our own Checker.
A list of the evidence acquired, with its hash values and chain of custody.
The analysis of metadata and of the consistency of dates, origins and headers.
Reasoned conclusions, with their limits, and ratification at trial if requested (quoted separately).

How we work

ConsultationWe assess the case and the material in a free call.
Fixed quoteWritten quote and advance payment before starting.
Acquisition and analysisWe extract the evidence with a chain of custody and analyse it.
Report and ratificationA report in line with UNE 197001:2019 and, if needed, ratification in court.

Turnaround: 10 working days

Price and terms

Prices are shown excluding VAT and with VAT included (21%).

From

€450 + VAT (€544.50 incl. VAT)

1 conversation or thread

Each additional conversation or thread:
€150 + VAT (€181.50 incl. VAT)

Technical hour

€95 + VAT (€114.95 incl. VAT)

per technical hour

Urgency

A surcharge of +50% on the service price, with delivery within 72 hours, where the case allows it.

Advance payment

Advance payment of 100% on engagements of up to €600. Above that amount, 50% on accepting the quote and 50% on delivery.

Ratification at trial

Ratification of the report at trial, in person, in Galicia, Asturias, León and Madrid.

A fixed written quote before starting.
The report follows UNE 197001:2019 and is checked with our own Checker before delivery.
Deadlines are working days from receiving the material and acceptance of the quote.
Prices are shown without VAT and with VAT included.

See all terms on the fees page →

Frequently asked questions

Do I need an expert to submit a WhatsApp conversation?

Not always. STS 116/2025 holds that an expert report is not always required to support a WhatsApp message, but that when it is challenged with reasons it is normally the expert report that proves its authenticity. A report is useful when the evidence is challenged with reasons, or when your case depends on it and you want to strengthen it.

Is it the same as a WhatsApp certification?

No. MEREBA issues expert reports, not qualified electronic certification. The report sets out reasoned technical conclusions, open to cross-examination, which the expert can ratify in court.

What do I need to provide?

The device or a complete copy of the conversation or mailbox. Do not delete or forward messages and do not reinstall the app: information may be lost.

How much does it cost with more than one conversation?

From €450 + VAT (€544.50 incl. VAT) per conversation or thread, plus €150 + VAT (€181.50 incl. VAT) for each additional one.

Can you say that a conversation is fake?

The report concludes what the data allow: it may find signs of tampering or it may not. We do not promise an outcome.

Regulations and case law

Shall we talk about your case?

Start with the free initial consultation: we will tell you whether a report is worthwhile and what material to keep.

Free initial consultation

Phone: +34 619 314 915 · Email: info@mereba.com