At European Union level, the COVID-19 Digital Certificate Regulation (Reg. (EU) 2021/953 of 14 June 2021) was adopted, which is directly applicable in all Member States from 1 July 2021 (it is set to be applied until 30 June 2022). Its aim is to ensure the free movement of citizens within the EU during the pandemic caused by COVID-19. The certificate provided for in the above Regulation contains an interoperable and machine-readable QR code, which must be provided on paper or digitally.