An emergency tax code is applied when HMRC does not have enough information about your income to give your employer the right tax code. This often happens when you start a new job and do not have a P45 from your previous employer, or when you start receiving a pension for the first time. The emergency tax code assumes you have no other income and no other allowances, which usually means you end up paying more tax than you should. Once HMRC receives information about your full situation, they will update your code and you will get a refund for any overpaid tax either through your payslip or directly from HMRC.
