p60 & Pay Slips Not Adding Up

cashbag

I would not write to the employer. You sound well-organised & competent so I would take all the paperwork you do have & any notes/calculations you have made & go along to talk to someone at your nearest Tax Office. Just say initially that you want advice. They are not ogres at HMRC & will take a dim view of an employer fiddling the payroll & tax records - if that is what they were doing. If they take your case seriously they can instigate an inspection of the employers payroll records & the employer will have to show them complete records, including copies of payslips produced. Don't worry about the cash payments & not signing for them. This is not initially about missing cash, it is about potential tax/NI fraud. If that is discovered then the cash is another issue. If your partner did not get the money it might be a lost cause, but if HMRC did not receive their dues they will take a dim view. It may well be of course that HMRC did receive all that was due, but the employer was retaining NET pay - which now would be almost impossible to prove.