https://www.slab.org.uk/faqs/cancellation-fees/
A cancellation fee will only be paid if the interpreter was not able to carry out any other work.
We will not pay for last minute cancellations that have been caused by you. In such circumstances you should expect to meet any cost billed by the interpreter.
If the client fails to turn up a cancellation fee will be paid. A maximum of one hour will be paid in these circumstances unless, of course, other work is undertaken at the same place or location.
A fee will be paid for the time spent waiting (up to a maximum of one hour) if your first client fails to turn up but other meetings are scheduled at the same location. However if any of the other scheduled meetings take place earlier due to the cancellation, we will only pay for the actual time spent waiting, which is the minimum charge of one hour being allocated to the first client actually seen.
If waiting time is chargeable this will be payable at the lower rate of £3.75 per quarter hour.