What is an aDOC format

aDOC is the official Lithuanian electronic document format used to digitally sign legally binding documents. It is widely used by individuals, businesses, and public authorities in Lithuania for secure electronic transactions.

An aDOC file is a basically a digitally signed container that can include one or more documents along with electronic signatures and related metadata. The format ensures the integrity of the documents and allows recipients to verify who signed them and whether the content has been altered.

aDOC is part of the Baltic e-signature ecosystem and is closely related to other regional formats such as Estonian BDOC (now replaced with ASiC), and Latvian EDoc. It is designed to work with qualified and advanced electronic signatures that comply with EU eIDAS requirements.

Lithuanian aDOC is a legally recognized electronic document format that complies with the EU eIDAS Regulation and Lithuanian national legislation. Documents signed in aDOC format can have the same legal effect as handwritten signatures, provided the signatures used meet the required level (advanced or qualified).

When an aDOC file is signed with a qualified electronic signature, it is legally equivalent to a handwritten signature across all EU member states. Advanced electronic signatures are also legally valid, though their evidentiary value may depend on context.

Although aDOC is legally binding throughout the EU, the format itself is primarily known and used in Lithuania. Many organizations and recipients in other EU countries may not be familiar with the aDOC format or have tools to open and validate it.

For international use, we recommend using more widely recognized formats such as ASiC containers or, preferably, PDF documents with embedded electronic signatures, which offer broader compatibility and a better user experience for recipients outside Lithuania.

As mentioned previously aDOC is a container-based electronic document format, technically built on the ASiC-E (Associated Signature Container – Extended) standard. In practice, an aDOC file is a simple ZIP-based container that bundles documents together with their electronic signatures and validation data.

A typical aDOC file contains:

The aDOC format ensures that:

Although aDOC files use a ZIP-based structure, it should always be handled as a single signed container. Extracting or modifying files inside the container will invalidate the signatures and the validation is no longer possible.

For more detailed and official information about the Lithuanian aDOC format, the following resources may be helpful:

If you are using aDOC within Agrello and encounter issues creating, opening, or validating documents, please contact Agrello Support for assistance.