https://www.slab.org.uk/faqs/transcribing/
When it is necessary to transcribe a recording, for example in situations where there is a dispute about what was said at an interview, only the relevant parts of the recording need to be transcribed rather than the whole recording.
The cost of transcribing will be based on the normal hourly rate of £30. Both the duration of the recording and the time taken to transcribe should be clearly noted by the interpreter.