Hello, I am Keith, one of the experts on Just Answer, and pleased to be able to help you with your question.
1. You should receive a share certificate from the company showing the shares you have bought.
2. 'When an option is exercised, income tax arises on the difference between the shares' market value on the date of exercise and their exercise price [source: Practical Law].
The employer is liable to account for income tax if the shares meet the necessary criteria. If the employer is liable, it pays income tax and employee NICs under PAYE, and employer NICs. If it is not liable, employees pay income tax under the self-assessment system, with no employee or employer NICs being payable.'
Finally when the shares are sold at some future, indeterminate date then Capital Gains Tax (CGT) will apply to any gain derived from the selling price and the exercise price. You have an Annual Exempt Amount (AEA), currently 11.1K, to offset any gain. In such schemes it is normal for the shares to be sold on the exercise date so there is no capital gain to tax.
I do hope that you have found my reply of assistance.