CGT

[Allen001]

Apologies if this has been posted before, but I am brand new to this forum.

Is there any way to estimate what the CGT implication will be when selling a particular share. As far as I can ascertain, ONST uses an averaging method to determine the base cost. If one has previously bought and sold a particular share, and / or if there was a split at some point, and / or if one received shares instead of dividends, then trying to establish a base cost in order to calculate the CGT when selling the shares becomes next to impossible for the average person. Does ONST not have the base cost of shares in one's portfolio somewhere?

Thanks in advance.

Al