The document issued by the registrar of companies to permit a public limited company to commence business is

Forming a public limited company involves more than one certificate. A Certificate of Incorporation is issued first, and it confirms that the company legally exists as a separate entity. However, a public company cannot start trading or borrowing money purely on the strength of that certificate.

Before a public company can commence business, the registrar of companies must issue a further document, the trading certificate, once the company has satisfied additional requirements such as showing that it has raised the minimum amount of share capital required by law. This certificate is the specific authorisation to begin trading.

It is easy to confuse this with the Certificate of Incorporation because both are issued by the registrar and both sound like permissions. The distinction matters: incorporation creates the company as a legal person, while the trading certificate permits that already-existing company to actually start operating. Memorandum and Article of Association are internal constitutional documents drawn up by the company itself, not certificates issued by the registrar to permit trading.

Exam takeaway: for a public limited company, incorporation and permission to trade are two separate steps, each marked by its own certificate.