Workers urged to check code that could mean they're paying incorrect taxKnowing your tax code is vital to understanding if you’re paying too much or too little to HMRC. ‌Occasionally, errors happen leaving people with the incorrect tax code and paying the wrong amount of tax as a result. The letters in your tax code usually change based on your circumstances, Lancs Live highlighted the full list and more tax code information can be found on the Gov.uk website. A 'K' at the start of a tax code usually suggests an alternative tax method is being applied. You can double check this using HMRC’s online tax code tool.