The National Insurance number
is a number used in the United Kingdom
in the administration of the National Insurance
or social security system. It is also used for some purposes in the UK tax system. Because it is one of two numbers (along with the NHS number
) allocated to almost every adult resident of the country, it is used for some limited purposes to check identity.
The number is sometimes referred to as a NINO
Allocation of number
People born and resident in the UK are assigned an NI number shortly before their 16th birthday. However, allocation of this number might occur a long time before this occasion (the date can usually be established from the prefix letters used), and siblings may have consecutive numbers - this is dependent on the payment of Child Benefit
Persons from abroad who wish to work in the UK, or those to whom a number was not initially allocated as children, may apply for a number through the Department for Work and Pensions
(DWP). The prefixes used are typically different from those used in the normal run.
The format of the number is two letters, six digits, and one further letter or a space. The example used is typically AB123456C. It is usual to pair off the digits - such separators are seen on forms used by government departments (both internal and external, notably the P45
In the case of AB 12 34 56 C
, the first and second letter cannot be D