Confused as to HMRC calculations for voluntary class 2 and 3 shortfalls

Hi, Would be very grateful if someone can give me some clarity! I'm a UK citizen, I've been living in Spain since I was 21 and working on and off for employers since then (33 years). I applied with the CF83 to pay nics, and included all my employment details. HMRC replied with a list of mixed class 2 and 3 shortfall rates from 2006 to now. I don't understand what the criteria are for paying the different rates. Without going into too much detail, an example would be: 2014-15 I worked a total of 10 weeks and am being asked to pay class 3 for 52 weeks of that year. 2020-2021, I also worked some 10 weeks and am asked for 10 weeks at class 3, and 42 weeks at class 2. 2019-2020 I only worked 12 days but am offered class 2 rate. I don't think I made mistakes in giving my employment record, so I don't understand how it's calculated and if I need to ask for a revision. Thanks for any advice!

Hi eod,
To be entitled to pay voluntary Class 2 National Insurance contributions whilst overseas, an individual must have been normally employed or self-employed in the UK before their departure and employed or self-employed overseas.
From the details that you’ve given it would appear that our International Team has not calculated the amount of voluntary lass 2 contributions correctly and they will need to look at this again.
If you could send them a letter to confirm your periods of employment/self-employment again and ask then to revisit their calculations.
Sorry for any inconvenience.
Thank you.

 

Thank you for the prompt reply. Can you tell me if I also need to include employment details of work I did before I left the UK? I worked short periods of time in a variety of different places as a student, some of which no longer exist. I'd assume hmrc have records of these since I have 3 years on my record. Many thanks.

Hi,
Any employment that you have had in the UK will be recorded on your National Insurance account so there is no need to include these details.  
If you could provide details of your overseas employment/self-employment then this would be helpful.  
Thank you.