How to buy missing years of NI self employed, after retirement age.

I have recently reached retirement age, but am not claiming my state pension yet, until I have topped up my NI contributions (missing years) I am self employed, and currently earn just over the threshhold to pay class 2. Do I need to pay class 4? I can't find any where to find out how to do this. I have phoned the Future pension, and the pension service, and had no joy. Very confused, can someone please help. Thank you

Hi Andrew, 
Class 4 National Insurance does not count towards your State Pension.
When you are self -employed, its only Class 2 National Insurance that counts towards your State Pension.
You will only be charged Class 4 National Insurance once your Self Employment profits exceeds £12,570 for the current tax year.
If your profit is below £12,570 you will not be charged Class 4 NIC 
Please see guidance here: 
Self-employed National Insurance rates
Thank you. 

I have a similar question, and the response ahove and the attached guidance are not clear to me. I have seen the HMRC guidance statement that “Class 4 NI does not count toward the State Pension.” However, I have also seen statements to the effect that (i) if you have paid Class 2 NI for a tax year, then that tax year is a qualifying year for State Pension purposes and (ii) “ If your profits are £6,725 or more a year: Class 2 contributions are treated as having been paid to protect your National Insurance record. This means you do not have to pay Class 2 contributions. If your profits are more than £12,570 a year, you must pay Class 4 contributions.”. These two statements together would indicate that, if you paid Class 4 contributions for a year, you are treated as having paid Class 2 contributions for that year, and the relevant year should therefore be a qualifying year. Can you please clarify this? Specifically, if one has paid Class 4 NI in a tax year due to a high level of self-employment income, is the relevant year a qualifying year for State Pension purposes? In my particular circumstances, I paid large amounts of Class 4 NICs in certain tax years, but they are showing as non-qualifying years on my record. Before making voluntary Class 3 contributions in respect of those years, I want to be sure that there wasn’t a mistake such that I should have been given credit for those years. Thank you.

Hi,
The arrangement where Class 2 was ‘deemed as paid’ only came into effect from 22/23 year so if you had high Class 4 payments we would need to know which years and also that you were correctly registered to pay Class 2 via National Insurance.  
We suggest call to check their account, National Insurance: general enquiries
Thank you.