A lot of public sector ones gave you no option but to opt out, and that ended in 2016, but at least it is all in one place. Contributions went up from 2016 to make the difference, may have been 1%.Regarding your second paragraph - contracting out via personal pensions ended in 2012 (although some providers chose to end before that date). So your contracted out payments could have carried on until 2012, but in all likely hood could have stopped before this date.
All dates and explanation in the Aberdeen (stupidly rebranded as Abrdn!!!) article below:
Contracting out
Techzone explains what contracting out was, how it worked under different types of scheme and how the abolition of contracting out affects the rights that had been…techzone.abrdn.com
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