Quick answer
For internationally trained occupational therapists, Grade B (350) in each of the four OET sub-tests is accepted for HCPC (UK) and AHPRA (Australia) registration. AHPRA's minimum for Writing is Grade C+ (300); Listening, Reading and Speaking stay at Grade B. The Writing sub-test tests your ability to summarise functional outcomes in structured prose. Most marks are lost on Organisation & Layout — narrative session-by-session recaps rather than outcome-first handovers.