For guidance on circuit amalgamations, please see here.
The circuit is normally a group of churches served by a team of ministers. Occasionally there are circuits with only one minister. A minister will have pastoral charge of one or more churches, but will preach and lead worship in different local churches in the circuit, along with local preachers. The arrangements for leading worship in a circuit are drawn up in a quarterly plan.
The circuit is led by the superintendent minister who presides over the circuit staff (both lay and ordained) and the circuit meeting, and with lay and ordained colleagues facilitates and encourages mission throughout the circuit. He or she is also responsible for drawing up the plan and arranging the gathering of information about activities (eg baptisms, weddings, and funerals) and about membership statistics in the circuit.
For more detail see the Conference report What is a Circuit Superintendent?
Responsibility for the direction and policy for the circuit is shared between lay and ordained. Voluntary circuit stewards have responsibility for maintaining, buying and selling circuit property (usually manses), and for the general welfare of the ordained and employed staff in the circuit. There is also a circuit treasurer.
The circuit is the place where new initiatives and changes in the pattern of church life need to happen. This is where the staffing capacity, where closures of chapels are debated, and where fresh expressions of church or new pioneer ministries are launched.