The additional State Pension, also known as the State Earnings Related Pension Scheme (SERPS) until it was changed to the Second State Pension (S2P), was abolished from 6 April 2016.
However, any entitlement to additional State Pension that you qualified for in the past may affect the value of your pension under the new State Pension scheme. You can check your pension entitlement on the GOV.UK web site.
People who are self-employed did not build up any entitlement to SERPS. And most people who had a salary-related pension would not have been entitled to SERPS for the period when they were building up benefits, as most salary-related schemes were 'contracted out' of SERPS arrangements.
SERPS was calculated on your pay over a maximum of 20 years. The only part of your pay which it took into account was the band between the National Insurance lower and upper earnings limits. Each year's pay within this band was uprated in line with inflation.
A maximum of 20 years of these revalued pay figures was then used to work out your SERPS pension. The maximum pension you can could receive from SERPS was 25% of your average band earnings.