Qualified electronic signatures and seals for companies in Bulgaria

A company in Bulgaria signs electronically in one of two ways: a person who represents it uses a qualified electronic signature (QES) that also names the company, or the company itself uses a qualified electronic seal. This page explains the difference, what Bulgarian providers ask a company to present, how joint representation affects the paperwork, and what foreign companies should expect. Checked on 28 October 2026. Our full guide for companies, КЕП за фирма, is in Bulgarian.

esign.bg is an independent guide, not a trust service provider. Providers are listed in alphabetical order and we have no commercial ties with any of them.

Representative signature or electronic seal

Under eIDAS only a natural person can be the signatory of an electronic signature. A company therefore signs through a manager, an employee or an agent whose qualified certificate contains both the person's and the company's data. Bulgarian providers sell this under names such as "professional" or "delegated" signature. Legally it is a QES of that person, with the equivalent effect of a handwritten signature (Article 25(2)).

An electronic seal is created by the legal person itself. eIDAS defines it as data attached to other data to ensure their origin and integrity (Article 3(25)), and a qualified seal enjoys a presumption of the integrity of the data and the correctness of their origin (Article 35(2)). B-Trust states on its required-documents page that a seal is issued only to a legal entity.

In practice:

• use a representative signature for declarations a specific person makes on the company's behalf: tax returns, Commercial Register applications, procurement documents, contracts;
• use a seal for documents the company issues in volume, such as invoices or certificates generated by a system, where no individual's statement is involved.

What providers ask a company for

Only what the providers' own pages say:

• B-Trust (BORICA AD): proof of legal status (a certificate of registration in the Commercial Register), the ID of the authorised representative, a notarised power of attorney on BORICA's template only if the company wants to appoint a representative, the contract signed by the person representing the company, and for each holder an ID and an online application. Templates are also offered in English.
• Evrotrust (Evrotrust Technologies JSC): its smart-card QES has separate packages for legal entities registered in Bulgaria (81.80 EUR) and outside Bulgaria (250.00 EUR), each valid for 2 years; the page lists no documents.
• InfoNotary (InfoNotary PLC): the applicant's ID; a certificate of registration or founding act if the organisation is not in a commercial or other public register; a notarised power of attorney if the holder is not the legal representative; a notarised power of attorney for a "bearer" who deals with the provider for the company; and a notarised request when you authorise someone else. More documents may be required depending on the legal form, the country of registration and the certificate type.
• StampIT (Information Services JSC): no extra documents for commercial companies registered with the Registry Agency; for other institutions, a document showing who manages and represents them; a notarised power of attorney if the holder is not the legal representative. It publishes two sample powers of attorney: one for a certificate in the name of the authorised person, one for a certificate in the name of the representative where the authorised person only handles the paperwork.

For eDocs we could not read the product pages; its website did not respond on 28 October 2026. Prices for all five providers are in our comparison (in Bulgarian).

Joint representation

Some companies are represented by two or more people who may act only together. Who represents a company is public: the Commercial Register file holds information on the governing bodies and on the persons representing the company, and anyone can search it free of charge on portal.registryagency.bg.

The providers' power-of-attorney templates we read (B-Trust's and InfoNotary's) are written for one principal: "the undersigned", acting as manager. None of the providers' document pages we read addresses joint representation. If your company's representatives can act only together, the safe order is:

1. Check in the Commercial Register how the company is represented.
2. Ask the chosen provider, before you go to a notary, how its form must be completed and signed when the representatives act jointly.
3. Have the power of attorney signed and notarised in that form.

Joint representation also matters when the company signs documents electronically. In the Registry Agency portal, an application lists every person who must sign it, each signs with their own QES, and the order does not matter; the application is submitted after the last signature.

Foreign companies

B-Trust publishes the clearest rules for a company registered abroad: documents issued in the country of registration, including a current extract; a power of attorney when someone else collects the signature; a copy of the ID when the signature is issued to a foreign citizen. They must be notarised, translated into Bulgarian by a sworn translator and apostilled, unless Bulgaria has a legal-assistance treaty with that country; notarisation by a Bulgarian consul is also accepted. B-Trust's FAQ adds that a foreign company may need additional documents. InfoNotary ties its extra documents to the country of registration, and Evrotrust has a separate package for companies registered outside Bulgaria.

A foreign company that already holds a qualified seal or its representatives' QES from another EU country does not need a Bulgarian one for legal validity: eIDAS recognises them in every Member State (Article 24a). Whether a given Bulgarian portal accepts them technically is a separate question; see our English guide.

Before you start

• Decide who will sign: the legal representative or an employee with a power of attorney.
• Download the provider's own template; providers require their own forms.
• When the representative authority changes (for example, a new manager), B-Trust's FAQ says a new certificate is needed instead of a renewal.

The providers' policies and practice statements are explained in trust service documents. To check a signature you received from a Bulgarian company, use our signature checker (interface in Bulgarian).