Don't you have any previous P60s? Unless a question is marked "optional" or "if known" I take it it's compulsory. However, if you don't have the reference you could add a note to your documents that you can't find it. It's probably not that critical because your NI number will l...

Hi, I just want to ask if the tax office reference number field on the online application is compulsory as I haven’t received my P60 yet and it is not included in my pay slip. I tried contacting the payroll department at my workplace but they take too long to reply to my emails and I just want to su...