Tax filing using e-ID (Mobile-ID/Smart-ID)

In Estonia, residents can file their tax return online with their national digital ID. Residents authenticate themselves on the e-tax portal through a verification code and their personal identification number (PIN1). After successful authentication and login, the portal automatically pre-fills tax return details, such as income and withholding. The system collects this data from employers, banks, and government registries and retrieves it through the X-Road platform. This follows the once-only principle, which ensures residents do not have to submit the same data again. Residents can review the pre-filled information, make any corrections, and submit their declaration by signing with PIN2 to create a qualified electronic signature.