Hi CLeo,
You must first speak to DWP (Future Pension Centre) before making any voluntary National insurance payments to HMRC.
If you are unable to get through on their helpline then you can request an interest in paying by completing the call back request form.
When you have had confirmation from the DWP of which years and how much you need to pay and that the payment will benefit your State Pension, then you can contact HMRC.
To be able to make a voluntary class 3 payments from a UK bank account you must use an 18 digit reference number.
We are experiencing a high volume of calls at the current time but we are taking measures to reduce the wait times.
The quietest time to call is the first and last hour the phone lines are open so between 8-9 am and 5-6 pm.
If you are unable to get through on the helpline to get your 18 digit reference number then you can contact us via webchat, please find the link below:
Contact HMRC
Alternatively, you could pay via cheque and if you do not have an 18 digit reference you can write you National Insurance number on the back of the cheque.
You must make the cheque payable to 'HM Revenue and Customs only' and along with the cheque send in a cover letter with the following information:
• your name
• your address
• your phone number
• your National Insurance Number
• what the payment is for - Class 3 National Insurance
• the period you are paying for
• a request for a receipt - if you want confirmation of the payment
Thank you