Signature or seal – the difference
An electronic signature expresses a natural person's consent to content. An electronic seal is linked to a legal person – a company, Chamber or authority. It is closer to a company stamp with built-in tamper protection.
Like signatures, seals have three levels under eIDAS: simple, advanced and qualified. A qualified seal is based on a qualified certificate issued to the organisation by a trust service provider.
Legal effect
Under Article 35(2) eIDAS, a qualified electronic seal enjoys the presumption of integrity of the data and correctness of its origin. In a dispute, the other party must prove the document was altered or did not come from the stated organisation. Qualified seals from one member state are recognised in all others.
Typical use cases
• Invoices: since 1 January 2025, businesses in Germany must be able to receive B2B e-invoices. A seal can additionally secure the origin and integrity of PDF documents. • Certificates and diplomas: Chambers and education providers issue documents that third parties want to verify. • Statements, policies and contract documents sent in high volumes by banks and insurers. • Archiving: a seal records a document's state at the time of archiving.
When to use a seal vs. a signature
Ask: must a specific person make a declaration? Then use a signature – for an employment contract or expert report, for example. Is the organisation confirming origin and integrity? Then a seal fits. Many processes combine both: a person signs, and the organisation then seals the result for the archive.
Implementation in practice
To introduce a seal you need a qualified or advanced seal certificate issued to your organisation. The trust service provider verifies the organisation's existence, for example via a commercial register extract, and the applicant's authority to represent it.
Next, define which document types are sealed automatically and at which point in the process – immediately after an invoice is created or before archiving, for instance. Test with recipients that the seal displays correctly in their validation tools.
Also consider long-term validation: certificates expire, but documents often need to remain verifiable for many years. Standards such as PAdES with long-term validation data help prove a seal's validity years later. Ask your provider how this is implemented.
Automation and integration
Seals deliver most value when applied automatically. Through APIs, documents can be sealed directly from ERP, invoicing or line-of-business systems – no manual step, no waiting. Define clear rules on which documents are sealed and protect the certificate so only authorised systems can use it.
Frequently asked questions
Does a seal replace the managing director's signature?
No. Where a personal declaration is required, a signature is still needed.
Can a seal be validated?
Yes, with common PDF readers and validation services that show certificate and integrity.
Does every organisation need a qualified seal?
No. An advanced seal is often enough internally. A qualified seal pays off when third parties need reliable proof of origin and integrity.
Are e-invoices valid without a seal?
Yes. Structured e-invoices in Germany require no signature or seal; a seal can add assurance for PDF documents.