NIM33606 - Persons going to and coming from abroad: Paying voluntary NICs - Going to countries not covered by the EC Regulations or a RA: Self-employed person
Schedule 2, Social Security (Categorisation of Earners) Regulations 1978
If a person is resident and employed in Great Britain as a self-employed earner, the employment is treated as continuing, until they are no longer self-employed in that employment.
If a person who is resident and self-employed in Great Britain, goes abroad for a short period, there is no provision which would remove any Class 2 NIC liability for complete contribution weeks while abroad.