The P9X is the guidance HMRC issue each year giving instruction for employers on the transition procedure for tax codes when moving from one tax year to the next. HMRC have just issued the 2016 P9X.
This year’s P9X is different from previous tax years in that employers are not only required to uplift “L” suffix codes but also the new codes “M” and “N” for those who are in receipt of, or who have given up some of their personal allowance under the Marriage Allowance rules.
