eIDAS-compliant electronic signature, built into every file.
Send the Acto de Compromiso, Acuerdo de Participación, Dictamen and D1-D5 for signature without leaving CertificAhorro. Full audit trail, SHA-256 hash, verifiable timestamp.
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How does it work?
How to sign a CAE file in 4 steps?
Select the document
From the file detail, choose the document you need to sign: Acto de Compromiso, Acuerdo de Participación, verifier's Dictamen, D1-D5 or any PDF generated by the platform.
Send for signature
Enter the signer's email (legal representative, beneficiary, verifier). CertificAhorro automatically sends the request with the file context and a secure link.
Sign from any device
The signer receives a link, confirms their intent to sign and signs from the browser. No installation, no prior digital certificate, compliant with Regulation EU 910/2014.
Audit trail archived
The signed document is automatically attached to the file with its full audit trail: SHA-256 hash, timestamp, signer's IP and browser, sequence of events. Immutable.
Evidentiary guarantees
What your client signs stays provable, indefinitely
Regulation EU 910/2014 (eIDAS)
The simple electronic signature (SES) meets the requirements of article 25 of the eIDAS Regulation. It cannot be denied legal effect or admissibility as evidence in legal proceedings solely on the grounds of its electronic form.
SHA-256 hash of the signed document
Each signature generates a cryptographic hash of the document that allows its integrity to be verified. Any subsequent modification of the PDF breaks the hash and invalidates the proof.
Verifiable timestamp
Each action by the signer (opening, reading, signing) is timestamped to the second. This makes it possible to prove the exact moment of signing in the event of a dispute.
Immutable audit trail
A record of the IP address, the user agent, the timestamps of each step and the exact sequence of events. Stored immutably in the file's database.
Signer identification
The signer validates their identity through their verified email address and the explicit confirmation of intent to sign. Compatible with standard CAE use cases (legal representative, beneficiary).
MITECO compatible
Signed documents are incorporated into the ZIP file using the official Sede MITECO naming convention. The audit trail travels alongside the PDF and remains available in any subsequent audit.
Documents covered
Which CAE file documents can be signed?
Acto de Compromiso (AC)
- Signature of the beneficiary's legal representative
- Before the start of works (art. 8 RD 36/2023)
- Critical blocking document
Acuerdo de Participación (AP)
- Signature of the beneficiary and the intermediary
- Assignment of the CAE
- Linked to the validated NIF/CIF
Verifier's Dictamen
- Signature of the ENAC-accredited verifier
- Structured declared/confirmed
- CO₂ coefficient and RDL 7/2026 multiplier
D1 to D5 (technical report)
- Signature of the responsible technician
- Compliant with Orden TED/845/2023
- Generated by CertificAhorro
Submitting the S1 form on the Sede MITECO requires a qualified electronic certificate from the legal representative and is done directly on the Sede. CertificAhorro generates the S1 form ready to submit.
Frequently asked questions about the eIDAS signature
What level of electronic signature does CertificAhorro use?
CertificAhorro implements the simple electronic signature (SES) compliant with article 25 of Regulation EU 910/2014 (eIDAS). This level is sufficient for the CAE file documents: Acto de Compromiso, Acuerdo de Participación, Dictamen and D1-D5. Submitting the S1 form on the Sede MITECO requires a qualified electronic certificate from the legal representative, which the signer provides on the Sede.
Does the simple electronic signature have evidentiary value?
Yes. Article 25.1 of the eIDAS Regulation establishes that an electronic signature shall not be denied legal effect or admissibility as evidence in legal proceedings solely on the grounds of its electronic form. The audit trail (SHA-256 hash, timestamp, IP, sequence of events) reinforces the evidentiary value in the event of a dispute.
Does the signer need a prior digital certificate?
No. The SES signature implemented in CertificAhorro does not require a prior digital certificate from the signer. A verified email address and the explicit confirmation of intent to sign are enough. This flexibility makes it possible to bring the beneficiary, the intermediary and the technician into the signing process without technical barriers.
What happens if the document is modified after signing?
The SHA-256 hash generated at the moment of signing is stored in the file's database. Any modification of the signed PDF breaks the hash and allows the alteration to be detected. The immutable audit trail also preserves the exact sequence of events of the original signature.
Is the electronic signature available on all plans?
Yes. The eIDAS SES electronic signature is available on all CertificAhorro plans, with no additional cost per signed document. Limits apply only to the file volume of the plan.
What is the difference between SES, AES and QES?
SES (Simple Electronic Signature) attests to the signer's intent with an audit trail; AES (Advanced) adds a unique link to the signer with tamper detection; QES (Qualified) requires a qualified certificate issued by an accredited trust service provider. For CAE file documents, SES is the level required by regulation. Submitting the S1 form on the Sede MITECO does require QES, which is done directly on the Sede.
Sign your files starting today
Available on all plans. No additional cost per signature. Full audit trail on every document.