ECMWF as the European Commission’s entrusted Entity for operating Copernicus Climate Change Service and Copernicus Atmosphere Monitoring Service, invites tenders to work with the ECMWF Copernicus Services’ Communications team by providing web services for the Copernicus Climate Change service (C3S) and the Copernicus Atmosphere Monitoring Service (CAMS) public websites and the Copernicus Health Hub (CHH) and Copernicus Energy Hub (CEH) websites: these websites are an essential part of the ECMWF Copernicus services communication channels to reach out to their audiences and promote scientific content, provide access to climate and atmospheric data, in case of the Thematic Hubs access to the Copernicus web ecosystem’s data, and keep the public informed with key environmental information.To this end, this Invitation to Tender (ITT) seeks to select a Tenderer to provide Website maintenance services.