Newbie:
it would appear that you CANNOT make contributions for previous years, unless you / they were already members of a registered scheme at that earlier point in time.
See this from Money Helper:
https://www.moneyhelper....-pensions/carry-forward
"Making use of unused annual allowances
Carry forward allows you to make use of any annual allowance that you might not have used during the three previous tax years,
Quote:provided that you were a member of a registered pension scheme during the relevant time period.
To use carry forward, there are certain conditions that need to be met. These include:
1. Contributions to your pensions must have used all of your annual allowance in the tax year you wish to use the carry forward rules.
2.
You must have been a member of a UK-registered pension scheme* (this does not include the State Pension) in each of the tax years from which you wish to carry forward from (you do not need to have paid any money into these schemes).