Two years ago Dynamic tax coding was introduced to make sure that people who have irregular pay or multiple jobs, can get a re-issued tax code during the tax year. HMRC uses its various information sources to make sure the new code is correct.
At the start of the tax year - the 2019 tax year starts next week - a default tax code is set. From April 2019 the new emergency tax code will be 1250L and this is derived from the standard personal tax-free allowance of £12,500.
As usual, since devolution of income tax, Scottish taxpayers will have their tax codes prefixed with an S.
Employees should contact HMRC about issues with their tax code on 0300 200 3300 - or online via gov.uk/reporting-your-tax-code-as-wrong.
Read our guide on tax codes for more information on how tax codes are calculated and how to correct incorrect information here