What is the completion of schooling called in UK?

There isn't one single term for the completion of schooling in the UK, as it depends on the level of schooling. Here are a few possibilities:

* Leaving school: This is a general term for finishing compulsory education (usually at age 16).

* Graduation: This refers to completing a higher education course, such as a degree at university.

* Finishing school/Completing your education: These are more general terms that could refer to any level of schooling.

Therefore, the most appropriate term depends on the context.