NIM20251 | Class 2 National Insurance contributions liability: Payment methods: Introduction
From HM Revenue & Customs · National Insurance Manual
Regulations 89 and 90 of the Social Security (Contributions) Regulations 2001 (SI 2001 No. 1004)
Where there was a liability for Class 2 National Insurance contributions (NICs) they could be paid by direct debit (DD) or in response to payment requests.