18 digit reference

Hi, I paid a 1 year gap of NI online via bank transfer using the 18 digit reference given and it updated my pension forecast within 5 days. However, a month later I paid another 2 year’s missing gaps online via bank transfer but it gave me a different 18 digit code only 8 of the numbers where the same I obviously used the new number thinking this was the correct thing to do but it’s been 8 working days and my pension forecast has not been updated. Should I be worried ?

Hi,
If you pay class 3 through your Pension forecast it can take up to 5 Working days to update. 
For all other payment methods such as bank transfer and cheque can take up to 8 weeks.
You can confirm these timescales here Pay voluntary Class 3 National Insurance
If there has been no change to your forecast after 8 weeks please contact national insurance. 
Call national Insurance on 0300 200 3500 from the UK or +44 191 203 7010 if calling from abroad.
You can use the webchat function ‘ask HMRC online’  Ask HMRC online
You can also write in to:
PT Operations North East England
HM Revenue and Customs
BX9 1AN
When submitting your correspondence, kindly provide your National Insurance Number, full name, current address, a contact telephone number, and a brief
explanation of the purpose of your letter.
Additionally, please remember to sign and date the document, even if it is printed.
Thank you.