Yes, aTax Id Uk is imperative to acquire employment in the UK since assures the state that no further changes must be made to your social security number. Employees require a National Insurance (NI) number so that they can get the correct tax and NI. This number is used by employers in order to report earnings to the HMRC. If you do not have a TIN, you may begin to have complications when processing payments as well as over payment of taxes. If you live in the United Kingdom but do not have this NI number you can apply for it through the HMRC upon presenting your I.D.and proof of residence.