Smart-ID is an app-based eID from SK ID Solutions, used to log in, register for e-services and sign documents. It's the main eID across the Baltics, with more than 3.2 million users in Estonia, Latvia and Lithuania, and from 2026 it's also available in Belgium on government portals such as MyMinfin and MyPension.

Smart-ID runs entirely on the user's phone or tablet. Unlike Mobile-ID it needs no special SIM, and unlike a card-based eID it needs no card reader. Anyone with a national identity number can register, using an ID card, passport, Mobile-ID, a bank link or a visit to a bank office. In Belgium users register with their national beID. Qualified electronic signature (QES) is the standard signature type for Smart-ID.

In eID Hub, Smart-ID is the provider smartID and supports both authentication and signing. A completed transaction returns the user's name, personal code and date of birth, along with their certificate and, for signing, the signature.