So just taking Nottingham's offerings as an example, there's
PGCE and
PGCEi. The PGCE is the real deal, full time, one year, and you get placed in classrooms as a teacher. Once done, you're qualified as a teacher (for, I presume, secondary school). The PGCEi by contrast is available online and part time, needs you to have access on your own to classrooms of students (ie probably already be employed as a teacher), and doesn't formally qualify you as a teacher. The PGCEi is an enrichment course.
What else is out there, I wonder. I'm kind of old to be getting new qualifications but I think becoming a subject teacher for high school could be worthwhile. Tertiary teaching needs formally fewer teaching qualifications but in principle if you're teaching in a university, you're supposed to be interested in academic research too. (I know it's in my contracts that they'd like it if I did papers and published them under the school's name.) And I think, given my relative late entry into teaching subjects other than English, then teaching at an introductory, or at least not the academically snooty, level could be a good fit. But it looks like teaching qualifications are required. Ads for positions teaching my preferred subjects, Business Studies (yay) and Economics (boo), seem to ask for PGCE and 2-3 years experience teaching secondary.
What's an old yet not retired man to do?!