I was on the BR tax code for 5 years from the year 2000

Basically, I was a little stupid and didn't bother getting around to getting an NI number for the first 5 years of my life in the UK from 2000-2005. So I was on BR. As a result, these years don't seem to count towards my state pension even though I was working full time the entire time. Is there anything I can do to have them reflected in my state pension?

Hi,
If you could send us copies of your P60s or the final payslip for the tax years involved then we’ll be able to trace for any contributions that were deducted from your salary and arrange for them to be recorded onto your National Insurance account.
Please send the copies with a covering letter to:
HM Revenue & Customs
PT Operations North East England
BX9 1AN
United Kingdom
Thank you.

Thanks for the reply. It's so long ago that I no longer have those documents. Are you able to look it up on your system?

Hi,
If you no longer hold P60s or payslips then please send us a letter with as much detail as possible about the name and address of your employer and the periods that you worked there (from … to …).  
We will then be able to try to trace for any National Insurance contributions.
Thank you.

Thank you. I no also no longer hold that information - it was such a long time ago. Would it be possible for someone to call me to discuss? I can provide you the dates I was working, my DOB, address etc but unfortunately I was working through recruitment agencies for most of that period. I appreciate this is tough. But please feel free to contact me directly rather than using the forum. Thank you again for taking the time to respond. - 

Hi
You will need to contact us either by writing to the address previously provided or by telephoning us.
Thankyou.