What's the difference between archiving and backup?

A backup is for restoring data after a failure: nothing guarantees that a backed-up file hasn't been modified, or that it will still be readable in 10 years. Probative archiving, by contrast, guarantees the integrity (any alteration is detectable), durability (standardised formats and media migration) and traceability (timestamped event log) of the signed document, so it stays enforceable in court for its full legal retention period.

Does electronic archiving have legal value?

Yes, provided the probative archiving standards are met. A document signed electronically and archived in line with NF Z42-013 or ISO 14641 keeps the same probative value as a paper original (French Civil Code, art. 1366 and 1379). Conversely, a plain PDF kept in a shared folder, with no integrity or timestamp guarantee, may have its value challenged in a dispute.

How long must a signed document be kept?

It depends on the document's nature: 10 years for commercial contracts and invoices (Commercial Code art. L123-22), 5 years for employment contracts, 6 years for tax records (Tax Procedures Book art. L102 B), 20 years for medical records, up to 75 years for notarial deeds. Archiving must cover that entire period, including the verifiability of the signature.

What is the NF Z42-013 standard?

NF Z42-013 is the French (AFNOR) standard defining the technical and organisational measures of a probative electronic archiving system. It governs the integrity, durability and traceability of archived documents and is the foundation of the NF 461 certification. Its international counterpart is ISO 14641.

What is the PAdES B-LTA format?

PAdES (PDF Advanced Electronic Signatures) is the ETSI standard for signing PDFs. The B-LTA (Long-Term Archival) profile embeds in the file everything needed to verify the signature years later — even after the certificate expires — by incorporating revocation data and renewing the timestamp. It is the reference format for long-term probative archiving.

Is archiving included in Certyneo?

Yes. Every document signed on Certyneo is archived in PAdES B-LT format, with a qualified RFC 3161 timestamp and 10-year retention included on all plans. The PAdES B-LTA profile, for retention beyond 10 years, is available on the Business plan. The event log and audit trail can be viewed and downloaded at any time.

What does eIDAS 2.0 qualified archiving add?

eIDAS 2.0 creates a qualified trust service dedicated to electronic archiving. Archiving performed by a qualified provider benefits from a presumption of integrity and automatic recognition across the European Union, on the same model as qualified timestamping or electronic seals. It is an extra guarantee for highly sensitive or cross-border documents.

Probative value · NF Z42-013 · ISO 14641

Archiving the signature: preserving probative value over time

Signing a document electronically is not enough: you must also be able to prove, in 5, 10 or 20 years, that the signature is authentic and the document unaltered. That is the role of probative electronic archiving — not to be confused with a simple cloud backup. Probative archiving rests on three pillars — integrity, durability and traceability — governed by the NF Z42-013 (AFNOR) and ISO 14641 standards. This guide explains what separates an archive that holds up in court from ordinary storage, the legal retention periods in France, the PAdES B-LTA format, and the new qualified archiving service introduced by eIDAS 2.0.

What is probative archiving?

Probative electronic archiving is the long-term retention of signed digital documents under conditions that guarantee their integrity, legibility and legal enforceability over time. A simple copy on a disk or cloud is not enough: a file can be modified without leaving a trace, its format can become unreadable, and nothing proves the date it was kept. Probative archiving addresses precisely these three risks.

It rests on three inseparable pillars. Integrity: the archived document cannot be altered, and any change is detectable — guaranteed by the cryptographic hash of the file at archiving and the periodic verification of that digest. Durability: the document stays readable for decades, regardless of software changes, which requires standardised formats (PDF/A for content, PAdES B-LTA for the signature) and regular media migration. Traceability: every operation on the archived document (deposit, access, disclosure, destruction) is recorded in a timestamped, tamper-proof event log.

Legal retention periods: who must archive, and for how long

In France, how long a signed document must remain enforceable is set by law according to its nature. Probative archiving only makes sense if it covers that full period — signature included.

Commercial contracts & invoices — 10 years

Commercial contracts and invoices are kept for 10 years (French Commercial Code, art. L123-22). It is the most common B2B reference period: the signed document must stay verifiable throughout, including the validity of the signing certificate.

Employment & HR documents — 5 years

A signed employment contract is kept for at least 5 years after the employee leaves; some payroll items run up to 50 years. Paperless HR therefore requires probative archiving able to cover long and heterogeneous horizons.

Tax documents — 6 years

Tax supporting documents are kept for 6 years (Book of Tax Procedures, art. L102 B). During an audit, the authorities can demand the signed digital originals: non-probative archiving has no enforceable value.

Notarial deeds — 75 years

Notarial deeds require 75-year retention (French Notary Code). Over such horizons, only archiving with format migration and timestamp renewal (PAdES B-LTA) keeps the signature verifiable beyond the lifetime of the certificates.

Medical records — 20 years

Medical records are kept for 20 years after the last act (French Public Health Code). For health-data hosts, probative archiving also requires HDS certification, which governs the security and confidentiality of the retention.

The regulatory framework for probative archiving

Four frameworks structure probative electronic archiving in France and Europe. Not all are mandatory, but compliance determines whether the archive is enforceable.

NF Z42-013 (AFNOR)

The French reference standard for probative electronic archiving. It defines the technical and organisational measures guaranteeing the integrity, durability and traceability of archived documents. It is the foundation of the AFNOR NF 461 "Electronic archiving system" certification.

ISO 14641 (international)

The international counterpart of NF Z42-013. It specifies the design and operation requirements of an electronic archiving system guaranteeing the fidelity and integrity of documents throughout their lifecycle, recognised beyond the French framework.

SIAF & third-party archiving

For the public sector and certain regulated activities, approval from the French Interministerial Archives Service (SIAF) or the use of a certified third-party archiver is required. The third-party archiver keeps documents on a client's behalf with a contractual commitment to probative value.

eIDAS 2.0 qualified archiving

The eIDAS 2.0 regulation introduces a new qualified trust service dedicated to electronic archiving. Qualified archiving benefits from a presumption of reliability and automatic recognition across the European Union — like qualified timestamping or electronic seals before it.

Probative archiving, backup, digital vault: what's the difference?

All three keep files, but only one guarantees probative value over time. Here are the six dimensions that set them apart.

Dimension	Probative archiving	Simple backup	Digital vault
Purpose	Guarantee the legal enforceability of a signed document over time.	Restore data after a failure or loss. No evidentiary purpose.	Store and share documents securely and personally.
Guaranteed integrity	Yes — hash at archiving + periodic verification of the digest.	No — a backed-up file can be replaced without a trace.	Partial — encryption and access control, but no enforceable proof of integrity.
Retention horizon	10, 20, 75 years — with format migration and timestamp renewal.	Short to medium term, per the backup retention policy.	As long as the subscription is active, with no format-durability guarantee.
Probative value in court	Strong — NF Z42-013 / ISO 14641 compliant, enforceable in disputes.	None — a backup has no standalone evidentiary value.	Variable — depends on the provider's contractual guarantees.
Format & durability	PDF/A + PAdES B-LTA, standardised long-term formats.	Original format, liable to become unreadable.	Original format, with no durability constraint.
Implementation	Built into the signing platform — no infrastructure to manage.	Low cost, but unsuitable for evidentiary use.	Per-user subscription, geared to individual use.

Frequently asked questions — electronic archiving

What's the difference between archiving and backup?: A backup is for restoring data after a failure: nothing guarantees that a backed-up file hasn't been modified, or that it will still be readable in 10 years. Probative archiving, by contrast, guarantees the integrity (any alteration is detectable), durability (standardised formats and media migration) and traceability (timestamped event log) of the signed document, so it stays enforceable in court for its full legal retention period.
Does electronic archiving have legal value?: Yes, provided the probative archiving standards are met. A document signed electronically and archived in line with NF Z42-013 or ISO 14641 keeps the same probative value as a paper original (French Civil Code, art. 1366 and 1379). Conversely, a plain PDF kept in a shared folder, with no integrity or timestamp guarantee, may have its value challenged in a dispute.
How long must a signed document be kept?: It depends on the document's nature: 10 years for commercial contracts and invoices (Commercial Code art. L123-22), 5 years for employment contracts, 6 years for tax records (Tax Procedures Book art. L102 B), 20 years for medical records, up to 75 years for notarial deeds. Archiving must cover that entire period, including the verifiability of the signature.
What is the NF Z42-013 standard?: NF Z42-013 is the French (AFNOR) standard defining the technical and organisational measures of a probative electronic archiving system. It governs the integrity, durability and traceability of archived documents and is the foundation of the NF 461 certification. Its international counterpart is ISO 14641.
What is the PAdES B-LTA format?: PAdES (PDF Advanced Electronic Signatures) is the ETSI standard for signing PDFs. The B-LTA (Long-Term Archival) profile embeds in the file everything needed to verify the signature years later — even after the certificate expires — by incorporating revocation data and renewing the timestamp. It is the reference format for long-term probative archiving.
Is archiving included in Certyneo?: Yes. Every document signed on Certyneo is archived in PAdES B-LT format, with a qualified RFC 3161 timestamp and 10-year retention included on all plans. The PAdES B-LTA profile, for retention beyond 10 years, is available on the Business plan. The event log and audit trail can be viewed and downloaded at any time.
What does eIDAS 2.0 qualified archiving add?: eIDAS 2.0 creates a qualified trust service dedicated to electronic archiving. Archiving performed by a qualified provider benefits from a presumption of integrity and automatic recognition across the European Union, on the same model as qualified timestamping or electronic seals. It is an extra guarantee for highly sensitive or cross-border documents.

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Signatures archived with probative value, by default

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