Groomsport EP has connections with a wide range of Presbyterian and Reformed churches in different parts of the world.
- EPC (The Evangelical Presbyterian Church in Ireland)
- EPCEW (Evangelical Presbyterian Church of England and Wales)
- IPC (The International Presbyterian Church)
- RPC (The Reformed Presbyterian Church in Ireland)
- FCOS (The Free Church of Scotland)
- FCOSC (The Free Church of Scotland Continuing)
- OPC (The Orthodox Presbyterian Church USA)
- PCA (The Presbyterian Church in America)
- Affinity (UK Evangelical Churches, Organisations and Individuals)
- The Associate Reformed Presbyterian Church
- First Presbyterian Church, Columbia SC