Buy back missed years UK state pension

This link is probably the most useful.

https:// community.hmrc.gov.uk/ customerforums/mtd/0be7d451-4cb2-eb11-89ee-00155d9c9e63

Sorry, Remove the spaces, since "New members are not allowed to post external links or emails for 7 days. Please contact the forum administrator for more information."

I submitted my CF83 at the beginning of January 2024. I checked the status online and it said that it was "In Progress", however when I checked waiting times, it said that I should expect an answer in December... At least HMRC are managing expectations!!

Yes, they told me it would be 6 months and it was.