Stopping Self-employment and Class 2 NICs

My husband retired from being a self-employed funeral celebrant on 30th June this year. Does he have to tell HMRC this straight away? He will be completing a self-assessment form at the end of the year. In addition, he has offered to take the odd funeral here and there if needed. There shouldn't be very many but I was wondering how this works where Class 2 National Insurance is concerned. Will he pay for days he works or does he have to continue paying throughout the whole year, including future years? He has reached the maximum for a state pension so voluntry Class 2 NICs isn't relevant.

Hi anniebuk,
With your husband still taking occasional self employment work, he is still self employed and Self Assessment would apply.  
After the end of this tax year (5 April 2024) you husband should confirm that Self Assessment is no longer appropriate to him, by checking the Self Assessment criteria tool Check if you need to send a Self Assessment tax return  
If he no longer meets Self Assessment criteria, he should contact our Self Assessment webchat collegues at:
Self Assessment: general enquiries
Our Self Assessement helpline ( currently closed until 4 September 2023) or by writing to HMRC at H M Revenue and Customs Self Assessment BX9 1AS, to advise the date self employment ceased and that SA criteria is no longer met.
For National Insurance matters, your husband should contact the NIC helpline at 0300 200 3500 (Monday to Friday: 8am to 6pm Closed on Saturdays, Sundays and Bank Holidays).
Thank you.