cgt & expenses
I'm not a tax expert but I doubt that such expenses would be considered allowable against gains when calculating CGT. Acquisition/disposal expenses (e.g. broker/agent fees), stamp duty (on purchases) and so on are allowed. Subscriptions to investment websites can hardly be deemed to enhance the value of an asset whatever about giving you guidance/information on the selection of assets (e.g. shares) to buy in the first place. I would imagine that such expenses would only be of relevance for tax purposes if you were engaging in a trade/business which involved the selection, purchase and disposal of capital assets. Otherwise I doubt that they would be allowed for most ordinary punters with capital investments.