Missing HRP records - how does my 83 yo Mum get the state pension payments she has missed?

15 years of HRP have been added to my Mum's NI record but the letter does not state how she will be refunded the state pension payments she has missed for the last 23 years. I've looked but can't find anything useful on the HMRC website. Any ideas?

Hi
If The Pension Service have not contact your mum about any increase in her State Pension then she may wish to call them on 0800 7310469 for an update.