Linking NI Class 2 Voluntary Payments to gaps / Confirming Payment

Applied with form CF83 to pay voluntary contributions. Received letter from HMRC indicating I am eligible to pay Class 2 contributions and historical gaps ( 10 years ) I have totaled this amount for this gap and paid via Revolut to account referenced in letter using Reference Number ( NI Number + IC + Surname ) Questions 1. Will my payment be added to all historical gap years? 2. Do I have to separately specify this somewhere? 3. I recognise time is needed for it to show up in my online account but is there a way to confirm payment has been received and will be allocated correctly?

Hi peaf54321,
It can take up to 8 weeks for your payment of voluntary contributions to be reflected on your Personal Tax Account (PTA).
Our International Team will allocate your payment to your National Insurance account and your PTA will reflect this.
If you could check your PTA after 8 weeks to ensure that your payment has been allocated as you intended.
If your payment has not been allocated after 8 weeks or not as you intended, then please call our National Insurance Helpline on 0300 200 3500 (from the UK) or +44 191 203 7010 (from overseas) and they will be able to help you.
National Insurance: general enquiries
Thank you. 

Hi peaf54321, I don't think the answer you got from HMRC above is entirely accurate. The stated goal is 8 weeks, but it's currently taking 2-5 months to show up! I made a contribution in May that still isn't showing up! However, you can chat with HMRC here https://www.tax.service.gov.uk/ask-hmrc/chat/national-insurance and they can at least confirm that they have received your payment.