NIM31013 | Special Cases: Widows: Widow living with a man as his wife during initial period
From HM Revenue & Customs · National Insurance Manual
Regulation 128 Social Security (Contributions) Regulations 2001 (SI 2001 No. 1004)
The initial period of reduced liability (see NIM31003) is not affected by a widow living with a man as his wife for part or all of that period.