Voluntary NI contributions to pay before 5th April 2025

I sent my form in March 2023 to pay for 6 years of voluntary NI Contributions from when I was in Australia. I have not heard anything as yet as I know you are very busy. I am in the UK and would like to know how to pay the lump sum to you before 5th April 2025 as I do not want to set up a direct debit . I understand I need an 18 digit ref number to make the payment? Will you advise me of your bank details to make this payment to you? Please could you advise me also of the form name as I hope I sent the correct one. As you are aware it is hard to get through on your help line so hoping this will help . Thank you.

Hi, I paid >£5k via the online process to pay for missing years NI contributions. I can see from my bank account that HMRC received this on 31st August, 2023. I had expected that my pension would increase in October, at the latest. I have just received my (November) state pension and it has remained at the same, old level. I have tried to find information online with no success. I have called (0300-) the number that you provided to the owner of this thread and am getting very bored listening to dreadful music and being told how much "useful information" there is on the .gov website. Perhaps someone could tell me where my updated pension is? That would be very "useful information" ...

Hi Deborah Walton,
The application form to pay voluntary contributions when a person has gone overseas from CF83 – Application to pay UK voluntary National Insurance contributions (NICs) 
We are currently working cases received on 01 January 2023 due to a surge in these types of requests.
Once we asses and process the CF83 we will be writing out with the tax years you will be invited to pay and how to make a payment.
You can make bulk amounts that are non direct debits at that point when you receive your response or calling us once completed the assessment and we have issued the letter, we can then advise you of the amounts and payment information over the phone before the letter arrives.
If you do wish to call HMRC in the future the national insurance line it is as below. It is always quieter when the lines open at 08:00am until 09:00. Please state overseas to the NI helpline automated voice when asked why you are calling.
In the UK – 0300 200 3500
Overseas - +44 191 203 7010
If you are 6 months from state pension age you will need to call an alternative number first – The International Pension Centre at the Department for Work and Pensions on:
In the UK – 0191 218 7777
Overseas - +44 191 218 7021
Thank you.