If you receive a task to close a self-assessment due to accounts changing it from self-assessment to a P87 then when you call HMRC you need to say the following
“We would like to close the following years. The reason they need closing is due to the client not being eligible to self-assess as the expenses are too low, so we are claiming through a P87”
One they agree to close the years requested you must set yourself a task for 3 days to check that this has been done. If it hasn’t been done, you must call back and do the same process. After the 2nd time of trying if they are still not closed set a task to the accountant for them to raise a complaint. Make sure you record the call log and detail the notes each time.
If HMRC advise that they can’t close, you need to task the accountant so they can raise a complaint with HMRC to get these closed.