Advice wanted re CGT calculation for shares held in Employer Profit Sharing Scheme

Hello, through my approved employer profit sharing scheme I acquired shares in 1991 and 1992. The scheme year lasted 12 months in both cases but the scheme was closed by my employer after 1992. The release date for shares in the scheme before I could access them without attracting tax was originally 1997 and 1998. I did not withdraw the shares from the scheme albeit the scheme was effectively closed. I left my employer in 2016 and sold the shares in October 2024. Should I use the market value of the shares at the date of my leaving my employer as the “base” cost for CGT purposes or should I use the market value of the shares as at the date the scheme was closed (i.e. 1993)? On a similar vein, in 1995 I joined my Inland Revenue approved, employer’s share saving plan using 1% of my after tax salary to purchase shares. Each share purchased was then matched with a matching share purchased on my behalf by the Scheme Trustees from contributions made by my employer. The scheme was closed by my employer in 2002. I did not withdraw the shares from the scheme. I left my employer in 2016 and sold the shares in 2024. Should I use the market value of the shares at the date of my leaving my employer as the “base” cost for CGT purposes or, should I use the market value of the shares as at the date the scheme was closed (i.e. 2002)? Thankyou.

Hi,
Please have a look a the guidance at:
HS287 Capital Gains Tax and employee share schemes (2024) and
ERSM180020 - CGT Interface).
Thank you.