The CF83 application form is for customers who want to pay voluntary National Insurance contributions for periods living abroad.
From the information you have provided, you would like to pay for a period when you were living in the UK, therefore the CF83 is not the correct application form for you to complete.
Your first step would be to contact the Department for Work and Pensions (0800 731 0175 lines are open Monday to Friday from 8am to 6pm) to find out if paying for the gaps in your National Insurance records will increase your pension.
Once you have confirmed that with them, you can either write to HMRC National Insurance contributions office to request a shortfall of the National Insurance contribution’s you can pay. See address below:
National Insurance Contributions & Employer Office
PT Operations North East England
HM Revenue and Customs
Or you can contact HMRC by telephone on 0300 200 3500 to request this information.
Alternatively, you can use the webchat facility - National Insurance: general enquiries
, choose the option ‘Ask HMRC online’.
This facility is available Monday to Friday from 10am to 6pm.