unauthorised

Unauthorised is the British English spelling of unauthorized, meaning not having official permission or authority to act. It describes actions, access, or information that are not licensed, approved, or sanctioned.

In security, unauthorised access is entry into a system, network, or facility without proper credentials or permission. In physical spaces, unauthorised entry can constitute trespass or breach of access controls.

In business and governance, unauthorised use of assets, unauthorised disclosure of confidential information, or unauthorised practice may violate laws, contracts, or professional standards, and can lead to penalties, disciplinary measures, or civil liability.

In copyright and media, unauthorised copying or distribution of protected material is illegal in many jurisdictions and is commonly referred to as piracy or infringement.

Etymology and spelling: formed from un- + authorised, British spelling; American English typically uses unauthorized. The term is used across legal, security, corporate, and regulatory contexts to denote actions or access lacking formal approval or authorization.

See also: authorization, authentication, consent, permission.