thank you for sharing your friends situation with us.
As for the questions, I found out the following:
For nationals from outside the European Economic Area (EEA) or Switzerland and subject to immigration control:
- give notice
- get married or form a civil partnership
Your friends and his partner must give at least 28 days’ notice at a designated register office if both the following apply to either of you:
For further information please follow the link:
I hope I could help, if there are more clearifiaction needed, please do not hesitate to use the community.