The UK eScience Certification Authority service (UKCA) is essential for the UK’s participation within multiple e-infrastructure projects, including WLCG and EGI. Communities from these projects require secure two-way communication that also provides a high level of assurance when authenticating its users and servers. This is achieved using “x.509” digital certi cates issued by a trusted authority. The UKCA provides this service for the UK academic and research communities and is trusted by the Interoperable Global Trust Federation . This ensures our certi cates can be used to authenticate users with a variety of Grid, Data, Compute and Cloud resources around the world.