National Insurance rates and categories

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Category letters

Employers use an employee’s National Insurance category letter when they run payroll to work out how much they both need to contribute.

Most employees have category letter A. Employees can find their category letter on their payslip.

Category letter Employee group
A All employees apart from those in groups B, C, H, J, M, V and Z in this table
B Married women and widows entitled to pay reduced National Insurance
C Employees over the State Pension age
H Apprentices under 25
J Employees who can defer National Insurance because they’re already paying it in another job
M Employees under 21
V Employees who are working in their first job since leaving the armed forces (veterans)
Z Employees under 21 who can defer National Insurance because they’re already paying it in another job

Category letters for employees who work in freeports

Employers use category letters F, I, L and S for employees who work in a freeport.

Category letter Employee group
F All employees who work in freeports, apart from those in groups I, L, and S in this table
I Married women and widows who work in freeports and are entitled to pay reduced National Insurance
L Employees who work in freeports and can defer National Insurance because they’re already paying it in another job
S Employees who work in freeports and are over the State Pension age

Category letters for employees who work in investment zones 

Employers use category letters N, E, D and K for employees who work in an investment zone.

Category letter Employee group
N All employees who work in investment zones, apart from those in groups E, D and K in this table
E Married women and widows who work in investment zones and are entitled to pay reduced National Insurance
D Employees who work in investment zones and can defer National Insurance because they’re already paying it in another job
K Employees who work in investment zones and are over State Pension age

Category letter X

Employers use category letter X for employees who do not have to pay National Insurance, for example because they’re under 16.

Mariners and deep sea fishermen

HMRC has detailed information on National Insurance for mariners and deep sea fishermen.