NIM25007 | Class 3 NICs: Restrictions on the right to pay: precluded Class 3 NICs: entitlement to credited NICs
From HM Revenue & Customs · National Insurance Manual
Regulation 49(1)(a) and (2) Social Security (Contributions) Regulations 2001
As explained in NIM25001, a person is not entitled to pay (i.e. is precluded from paying) Class 3 NICs for any week(s) where they are entitled to an NI credit. Up until 6 April 2016 this regulation was subject to the qualification in NIM25011. From 6 April 2016 the payment of Class 3 NICs now only provides for entitlement to new State Pension and the qualifications in NIM25011 no longer apply. See NIM41000 onwards for information on the types of NI credits a customer could be entitled to.
Example
Mr Ward is not working and is living on savings. Having got a pension forecast several years ago, he knows that he will not get a full new State Pension. Although that has not really bothered him too much in the past he decides to increase his entitlement to State Pension by paying 52 Class 3 NICs for the 2018-19 tax year.
As it turns out, Mr Ward is entitled to NI credits for the 2018-19 tax year. Once any credits are awarded the Class 3 NICs are not required for the purposes specified in regulation 49(2) (see NIM25010) and he has become precluded from paying them under regulation 49(1)(a).