Parties to the Pool include potential Pool Members and Service Providers. A Party accedes to the P&SA but is not entitled to trade. Becoming a Party is the first step in the process of joining the Pool.

Before being able to trade in the electricity market you need to become a Pool Member which involves satisfying the terms of the P&SA. Pool Members are entitled to trade electricity either as a Generator, Supplier or both.

The Service Providers supply services which assist in the operation of the Pool and they are bound by the terms of the P&SA. The roles are fulfilled by subsidiaries of the National Grid Company.

A number of obligations must be satisfied prior to becoming a Party or Pool Member. The CEO's Pool Membership Administrator (PMA) co-ordinates the membership process and ensures that all conditions of membership are satisfied.