thankyouthankyouthankyou, Ksand. You are the best as always!
My HR letter is dated 14 January, so that is within 28 days of 4 Feb (because HR is impossible to get stuff from!).
Also, pay slips can be printed offline now, right, and not stamped, since they are scanned/uploaded? I have originals of everything else - bank statements, p60s, mail, passports...