NIM30009 - Special Cases: Married Women: Employer's liability if certificate of election/reduced liability not held
Regulation 133(3) of the Social Security Regulations 2001
An employer must deduct Class 1 contributions at the standard rate unless they have got a valid certificate of election/reduced liability from their employee. Only women born on or before 5 April 1961 and who were married on or before 5 April 1977 were able to elect to pay primary Class 1 contributions at the reduced rate.