Product facts

What is SealDoc?

SealDoc is EU-sovereign evidence infrastructure for documents. SealDoc requests an RFC 3161 timestamp for each document from an independent Time Stamping Authority and records it on an append-only, tamper-evident SHA-384 hash chain, so any later change is provable. You get a Legal Evidence Pack that can be verified independently. SealDoc is built and hosted in Europe by FeFem Holding B.V., on infrastructure we manage ourselves, and it never claims more than it can prove.

What SealDoc does

Your ERP or accounting software generates the invoice. SealDoc adds the proof layer on top: it converts the document to archival PDF/A-3, requests an RFC 3161 timestamp from an independent Time Stamping Authority, records every action in a tamper-evident audit trail, and bundles everything into one Legal Evidence Pack you can hand to an auditor, a tax authority or a court. One API call in, a validated document plus its proof out. SealDoc never claims more than it can prove: each guarantee in the pack is asserted only when its backing proof is present.

The six layers that turn a document into evidence

PDF/A-3B archive format

ISO 19005-3 validated by VeraPDF. The only PDF format designed for long-term archival — preserves all content without external dependencies.

RFC 3161 timestamp

Cryptographic proof the document existed at a specific time, issued by a trusted RFC3161 Time Stamping Authority. Embedded in the Evidence Pack.

Tamper-evident hash chain

SHA-384 hash of every document, linked in an append-only evidence chain. Any modification — one byte — invalidates the chain.

Chain of custody

Every action on the document is logged: who did what, when, from which IP. Written to a tamper-resistant audit log.

Retention enforcement

SealDoc will not delete a document before its retention period expires.

Legal Evidence Pack

One ZIP containing the document, audit trail, timestamp token and manifest hash-chain. For audits, tax inspections and disputes.

Who makes SealDoc?

SealDoc is a product of FeFem Holding B.V., a European company. All infrastructure runs in EU datacenters certified to ISO 27001, and your data stays in the European Economic Area. The document proof platform SealDoc is the one at sealdoc.eu.

Frequently asked questions about SealDoc

What is SealDoc in one sentence?
SealDoc is EU-sovereign compliance infrastructure that records an RFC 3161 timestamp, a tamper-evident hash chain and a chain of custody for each document, with a Legal Evidence Pack on request, so you can prove years later that the document existed and has not been altered.
Who operates SealDoc?
SealDoc is a product of FeFem Holding B.V., a European company. It is built and hosted entirely in the EU, on infrastructure we manage ourselves.
What does SealDoc actually produce?
For each document, SealDoc returns a PDF/A-3 file validated with veraPDF, and on request a Legal Evidence Pack: the PDF/A-3 document, the audit trail, the RFC 3161 timestamp token and a manifest with the hash of every file.
Which standards does SealDoc support?
RFC 3161 trusted timestamping, PDF/A-3B (ISO 19005-3) archival format, Factur-X, ZUGFeRD and XRechnung e-invoicing, Peppol BIS 3.0, the EN 16931 invoice data model, and SHA-384 evidence hashing.
Where is SealDoc data stored?
All data is processed and stored in EU datacenters certified to ISO 27001, on infrastructure we manage ourselves. With your own storage (BYOS) on Enterprise, you decide where your data is stored.
Does SealDoc have a free plan?
Yes. The Developer plan is permanently free: 50 documents per month, full API access, and complete pipeline output including PDF/A-3B and embedded XML. No credit card required.
What is an RFC 3161 timestamp?
An RFC 3161 timestamp is cryptographic proof that a specific document existed at a specific point in time and has not been altered since. SealDoc submits a hash of your document to a trusted RFC 3161 Time Stamping Authority, which signs the response. The result is embedded in your Evidence Pack and can be verified independently by anyone.
What is a Legal Evidence Pack?
A Legal Evidence Pack is one ZIP file containing the PDF/A-3 document, the audit trail, the RFC 3161 timestamp token and a manifest with the hash of every file. You can hand it to an auditor, a tax authority or a court.

See it work

Start free with 50 documents per month, or read the API docs. No credit card required.

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