I know I have missed the deadline to top up pension in UK but what I am looking for help on is finding out my NI from the 1980's. Unfortunately I dont remember the address I lived at when I received my NI number, worked off line a bit and also on unemployment benefit back n the day. Tried the web site GOV.UK and filled in forms and sent to Individuals Case Worker @HMRC in NE England BX9 1AN in September 2024 but never heard anything back. Any help or guidance much appreciated