The Trefoil Guild is for all the women above the age of 55 years. This is part of the Guide Movement but it is independently administered and is financially self-supporting. Its aims and objectives are:

•  To keep alive among members the spirit of the Guide Promise and Laws.
•  To carry that spirit into the communities in which members live and work.
• To give practical, financial and moral support to Guiding. It is recommended that every Division and/or District should have at least one Trefoil Guild.

Membership to the Trefoil Guild is achieved through admission into membership of a Guild or through the Bravo Guides.
There are four categories of membership:
Full, Associate and Affiliate and Honorary Associate