A statement given to you by your employer in April each year showing how much you were paid and what tax you coughed up on it. Used by underwriters to check that what you said in your application form is true.
A P60 form is the end of year certificate of pay and tax deducted under PAYE (Pay As You Earn). It shows an employee's total amount of pay for income tax purposes, along with how much has been deducted in tax and National Insurance over the tax year. If your employer doesn't give you a P60 at the end of the tax year, ask for it you might need it: to complete a Self Assessment tax return, if this applies to you, to claim back any tax you've overpaid or to apply for Tax Credits. You may also need it as proof of your income if you apply for a loan or a mortgage - so it's important to keep all your P60s safe. If you've lost your P60 your employer can issue you with a duplicate - but this must be clearly marked as being so.