Picture posting is enabled for all :)
Who is likely to be affected? You might have under or overpaid tax if: Your employer used the wrong tax code, you started a new job and had an emergency tax code for a while,you only worked for part of the year, you had more than one job at the same time, you didn't tell HMRC right away about changes to benefits you got through your work, your circumstances changed - perhaps you were made redundant or became self employed and therefore your income reduced, other income like investments or rental income reduced but you didn't tell HMRC or HMRC made a mistake with your tax.