ADOC, ASiC-E and PDF

ADOC: how to open, check and sign a .adoc file

ADOC is the Lithuanian electronic document container. If a Lithuanian counterparty or authority has sent you a .adoc file, this is what it is and what to do with it.

Updated: 2026-08-20 Query: how to open an ADOC file received from Lithuania and sign it

What an ADOC file is

ADOC is not a PDF with a picture of a signature in it. It is a container, and it can hold the document, its attachments, metadata and XAdES signatures.

The tools of the Office of the Chief Archivist of Lithuania and the ePaslaugos government portal show what the format is for: creating, signing and checking electronic documents to the Lithuanian specification.

Opening one you have received

Two things matter when a .adoc arrives: reading what is inside it, and confirming that the signatures on it hold. They are different operations, and only the second one tells you whether the document can be relied on.

Tvarka reads the container and shows its contents, and the signature check tells you who signed and whether anything changed afterwards. The ePaslaugos validator is the public, independent alternative.

Working in Tvarka

The Tvarka Sign ADOC wizard builds an ADOC archive from your documents. They are converted to signable PDF or PDF/A versions before the archive is assembled, or the original file is embedded as it is (this is what happens with XLSX files).

The contents of an uploaded ADOC can be previewed and extracted. To sign, use QES: Smart-ID, Mobile-ID, LT ID, USB/eID or the NFC route.

Frequently asked questions

Can I just rename it to .zip?

Technically you will see the files inside, but that tells you nothing about whether the signatures and metadata are sound. Use a verification tool or the Tvarka preview.

Is ADOC accepted by Lithuanian public authorities?

Yes, where the institution asks for ADOC or accepts the format. Always check what the specific recipient requires.

Can Tvarka build an ADOC with attachments?

Yes. The ADOC wizard exists to put a main document and its attachments into a single container.

Do I need ADOC, or will a signed PDF do?

That depends on the recipient. A PDF with a PAdES signature is enough for ordinary business documents; ADOC is what some Lithuanian institutions specifically ask for.

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