ADOC, ASiC-E and PDF

EU signature format rules from 2027: what Regulation (EU) 2026/248 changes

From 23 February 2027 public sector bodies have to recognise five EU signature formats. What changes, which deadlines apply, and what it means for ADOC.

Updated: 2026-08-20 Query: regulation 2026/248 electronic signature formats 2027 public sector XAdES CAdES PAdES JAdES ASiC

What was adopted, and when it applies

On 2 February 2026 the European Commission adopted Implementing Regulation (EU) 2026/248, replacing Decision 2015/1506, which had been in force since 2015. The Regulation sets out which advanced electronic signature and electronic seal formats public sector bodies in the EU have to recognise.

From 23 February 2027 a public sector body that requires an advanced electronic signature for an online service has to recognise every format listed in Annex I to the Regulation. That includes public procurement, where suppliers submit electronically signed documents.

There is a transition: signatures built to the older specifications are recognised only if they were created before 23 February 2028.

The five mandatory formats

Annex I covers four signature formats and the standardised containers. All of them are built on ETSI Baseline profiles:

  • XAdES - XML-based signatures, used inside both ADOC and ASiC-E containers.
  • CAdES - CMS signatures, most often seen as .p7s files.
  • PAdES - signatures inside PDF documents.
  • JAdES - JSON-based signatures, meant for machine interfaces (APIs).
  • ASiC - containers for several files and signatures, including ASiC-E with CAdES signatures.

What happens to ADOC

ADOC is not going away: documents already signed stay valid, and Lithuanian institutions may keep accepting it after 2027. But ADOC is not among the Annex I formats, so its recognition in other Member States depends on a separate national verification mechanism.

The direction is clear. From 2027 the European formats become the mandatory minimum in the public sector. For new documents it is worth choosing the standard EU formats and keeping ADOC for the cases where a particular Lithuanian institution asks for it.

How to prepare

What you need to do depends on whether you sign documents or receive them.

  1. Check which formats your signing tool produces today: PDF (PAdES), ASiC-E, or only ADOC.
  2. Contracting authorities and other public sector bodies: make sure your systems accept and verify every Annex I format by 23 February 2027.
  3. Businesses: agree the format in advance and avoid depending on a single national format.

Where Tvarka stands

Tvarka supports all five formats listed in Annex I to Regulation (EU) 2026/248. Conformance of the XAdES, CAdES and PAdES signatures to the Baseline profiles was checked with the reference DSS validator of the European Commission, JAdES signatures are issued by the Tvarka API, and ASiC-E containers are supported with both XAdES and CAdES signatures.

Tvarka Sign also continues to support ADOC, so through the transition you can work in both the national and the European formats. Format conformance is re-checked automatically.

This is not individual legal or tax advice. Before deciding on a specific transaction, tax situation or dispute, assess your own circumstances.

Frequently asked questions

Do ADOC documents that are already signed stop being valid?

No. A document that has been signed stays valid. The Regulation does not invalidate existing signatures; it sets out which formats public sector bodies have to recognise in future.

Does the Regulation apply to private business too?

Directly it binds public sector bodies only. In practice these formats will become the business standard as well, because the same tools are used to file documents with authorities.

What is a Baseline profile?

It is a set of ETSI standards that defines exactly which elements a signature has to contain so that every system reads it the same way. The Regulation names the specific standard versions for each format.

Does an ordinary user need JAdES?

No. JAdES is for machine interfaces, where applications exchange documents. People will usually sign a PDF (PAdES) or an ASiC-E container.

From when are the requirements binding?

The obligation to recognise the Annex I formats applies from 23 February 2027. Signatures built to the older specifications are recognised if they were created before 23 February 2028.

Sources