I heard that there is an age limit. No one over 35 or so is admitted? True?
Under the Equality Act 2010 employers can not discriminate on the basis of age. However, graduate schemes will generally only be open to people who have recently graduated; within the past 5 years for example.
I believe further degrees can be done at any time via the Open University, OP.
If you mean graduate programs in the sense of Masters level programs, then that isn't true. I returned to school in the UK to get an MBA at age 37... and I wasn't the oldest in my cohort.