If your company is a private company, it doesn't need to have a company secretary. It will need a company secretary if it's a public company.
You can appoint a company secretary at the time you register ('incorporate') the company by naming them on Form IN01. The shareholders must confirm on this form that the directors and secretary named on the form have consented to act. Alternatively, you can appoint the company secretary after incorporation. If you do so, you need to tell Companies House of the appointment by using Form AP03.This form includes a statement by the company that the secretary has consented to act.
If you're removing a secretary from your company, you must tell Companies House by using Form TM02.
If your company has a secretary, it must maintain at Companies House a central register of secretaries containing the name and service address of the secretary. The service address is used to receive communications from third parties about the company. All changes to the information the register contains must be reported by the company as soon as the change occurs.
If you think you might appoint a secretary after incorporation, you should include an article in your articles of association (your company's set of rules) giving the board of directors power to appoint and remove a company secretary by passing a board resolution. The default ('model') articles for private companies don't contain this article as they're designed for a company without a secretary.
The company secretary of a private company doesn't need any formal qualifications.
The company secretary of a public company must meet the qualifications set out in the Companies Act 2006.
The company secretary's duties depend on what the directors decide to ask the company secretary to do. A company secretary might typically do any of the following:
As the secretary is an officer of the company, they may be criminally liable for defaults of your company, e.g. for the company failing to file required company information in time.