You might already have a National Insurance number if you applied for any benefits or have one on your BRP.

If you do not have one, you need to apply for a National Insurance number to work in the UK.

ENG:

https://www.gov.uk/apply-national-insurance-number

UKR:

https://www-gov-uk.translate.goog/apply-national-insurance-number?_x_tr_sl=auto&_x_tr_tl=uk&_x_tr_hl=en