I received a letter from HMRC yesterday which said that I owe them £1600 in unpaid tax from 2012/13. I checked their figures and called them and it seems that my employers have given them an incorrect figure regarding how much I earnt in this period. They've somehow doubled it and then some!
Of course, I can't find my P60 OR any payslips from this period so I'm having to go back to my ex employer and hope they will be able to provide a duplicate P60 or a statement of earnings for the year.
Fingers crossed for me! I definitely didn't earn that much in that year but at the moment, it's up to me to prove that I didn't. Something that would easily be done with a P60! Gah!