How do I solve 12 across in Daily Telegraph Cryptic 31254?

Question

Accepted Answer

12 across reads "Confess Cambridge University's on notice" (5 letters); the answer is ADMIT. It's a charade: the answer breaks into parts in clue order, each part clued by a word or short phrase. No indicators needed; watch for standard abbreviations (RA = artist, US = American, IN = at home) and short synonyms. The full step-by-step breakdown is on this page.

Confess Cambridge University's on notice (5)

12A — Confess Cambridge University's on notice (5) — ADMIT