You can issue as many shares as you like when forming the company, or after the company has been set up. Many people choose to put a round number, such as 1, 10 or 100 shares at £1 per share, so it is easy to work out the percentages of ownership.

A common example is 100 shares at £1 per share. If you own all 100 shares, you will have 100% ownership. If you own 90 shares and someone else owns 10 shares, you will own 90% of the company

It is also worth considering that your shares relate to your liability in the company, so if you have £100 shares at £1 per share, you will be liable to pay up to £100 should the company face financial difficulty.