Each employee in Great Britain should have their own one-time National Insurance Number (equivalent to the Polish Tax Identification Number - NIP), known as NIN.
NIN is used to register the taxpayer in the social insurance system and the tax system. This allows to collect benefits and retirement. After an employee is given a Social Security Number, the employer participates in his/her social insurance.
The number consists of 2 letters, 6 digits and one letter at the end: e.g. AB 123456 C.
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