You’ll usually need a sponsor licence to employ someone to work for you from outside the UK. This includes citizens of the EU, Iceland, Liechtenstein, Norway and Switzerland who arrived in the UK after 31 December 2020.
This includes unpaid work, like running a charity.
You will not need a licence to sponsor certain groups, for example:
Sponsoring someone does not guarantee that they’ll be allowed to come to or stay in the UK.