NIM71100 - Class 2 National Insurance contributions: international: retention of records
Regulation 148C Social Security (Contributions) Regulations (SSCR) 2001 (SI 2001 no 1004)
Self-employed earners abroad who remain subject to UK National Insurance contributions by virtue of EC Regulations or an international social security agreement (see NIM33000) will be required to retain the records relating to calculating whether there was a Class 2 NICs liability – expressly the records used to compute relevant profits.
These records must be made available to HMRC on request.