| School | HMC Division | Membership | Location | Age Range |
| Lomond School | Scottish (UK) | British Isles | Helensburgh, United Kingdom | 3 - 18 |
| St Helen and St Katharine | South Central (UK) | British Isles | Abingdon, United Kingdom | 9 - 18 |
| St Helens’s School | London (UK) | British Isles | Northwood, United Kingdom | 3 - 18 |
Lomond School
Age range
3 - 18
Location
10 Stafford Street, Helensburgh, Argyll & Bute, Scotland, G84 9JX, United Kingdom
Head’s name
Claire Chisholm
St Helen and St Katharine
Age range
9 - 18
Location
Faringdon Road, Abingdon, Oxfordshire, OX14 1BE, United Kingdom
Head’s name
Rebecca Dougall
St Helens’s School
Age range
3 - 18
Location
Eastbury Road, Northwood HA6 3AN, UK
Head’s name
Bridget Ward