HMRC publish guidance on “how income tax and NICs rules work if you’re a share fisherman”. The guidance has been updated with “information … about Class 2 National Insurance contributions if your profits are between the Small Profits Threshold and the Lower Profits Threshold”.
(For details of NIC figures generally for the current tax year, see https://claritaxnews.com/personal-taxes/nic-class-2-figures-confirmed-for-current-tax-year-si-2022-1329/).
Related content from Claritax Books
The complex rules for National Insurance contributions are covered in depth in National Insurance Contributions, by Karen Speight.