| School | HMC Division | Membership | Location | Age Range |
| Abbey College Cambridge | East (UK) | British Isles | Homerton Gardens, Cambridge, CB2 8EB | 13 - 18 |
| Abingdon School | South Central (UK) | British Isles | Abingdon, United Kingdom | 11 - 18 |
| Ackworth School | North East (UK) | British Isles | Pontefract, United Kingdom | 2 - 18 |
| ACS International School Cobham | South Central (UK) | British Isles | Cobham, United Kingdom | 3 - 18 |
| Aiglon College | International | International | Ollon, Switzerland | 9 - 18 |
| AIS Saigon | International | International | , Vietnam | 1 - 18 |
| Akademeia High School | International | International | Warszawa, Poland | 13 - 18 |
| AKS Lytham | North West (UK) | British Isles | Lytham St Annes, United Kingdom | 0 - 18 |
| Albyn School | Scottish (UK) | British Isles | Aberdeen, United Kingdom | 2 - 18 |
| Aldenham School | London (UK) | British Isles | Borehamwood, United Kingdom | 0 - 18 |
| Alleyn’s School | London (UK) | British Isles | Dulwich, London, United Kingdom | 4 - 18 |
| Altrincham Grammar School for Boys | North West (UK) | Associate (UK) | Altrincham, United Kingdom | |
| Ampleforth College | North East (UK) | British Isles | York, United Kingdom | 11 - 18 |
| Ardingly College | South East (UK) | British Isles | Haywards Heath, United Kingdom | 2 - 18 |
| Ashford School | South East (UK) | British Isles | Ashford, United Kingdom | 0 - 18 |
| Ashville Harrogate | North East (UK) | British Isles | Harrogate, United Kingdom | 2 - 18 |
| Badminton School | South West and Wales (UK) | British Isles | Bristol, United Kingdom | 3 - 18 |
| Bancroft’s School | London (UK) | British Isles | Woodford Green, Essex, United Kingdom | 7 - 18 |
| Bangkok International Preparatory & Secondary School | International | International | , Thailand | 3 - 18 |
| Bangor Grammar School | Irish | Associate (UK) | Bangor, United Kingdom | 13 - 18 |
| Barnard Castle School | North East (UK) | British Isles | Barnard Castle, United Kingdom | 4 - 18 |
| Bedales School | South Central (UK) | British Isles | Petersfield, United Kingdom | 3 - 18 |
| Bede’s School | South East (UK) | British Isles | Hailsham, United Kingdom | 13 - 18 |
| Bedford Modern School | London (UK) | British Isles | Bedford, United Kingdom | 7 - 18 |
| Bedford School | London (UK) | British Isles | Bedford, United Kingdom | 7 - 18 |
| Belfast Royal Academy | Irish | British Isles | Belfast, United Kingdom | 11 - 18 |
| Benenden School | South East (UK) | British Isles | Cranbrook, United Kingdom | 11 - 18 |
| Berkhamsted School | London (UK) | British Isles | Berkhamsted, United Kingdom | 0 - 18 |
| Birkdale School | North East (UK) | British Isles | Sheffield, United Kingdom | 4 - 18 |
| Birkenhead School | North West (UK) | British Isles | Wirral, United Kingdom | 0 - 18 |
| Bishop Wordsworth’s School | South Central (UK) | Associate (UK) | Salisbury, United Kingdom | 11 - 18 |
| Bishop’s Stortford College | East (UK) | British Isles | Bishop's Stortford, United Kingdom | 4 - 18 |
| Bloxham School | West (UK) | British Isles | Banbury, United Kingdom | 11 - 18 |
| Blundell’s School | South West and Wales (UK) | British Isles | Tiverton, United Kingdom | 11 - 18 |
| Bolton School | North West (UK) | British Isles | Bolton, United Kingdom | 0 - 18 |
| Bootham School | North East (UK) | British Isles | York, United Kingdom | 3 - 18 |
Abbey College Cambridge
Age range
13 - 18
Location
Homerton Street, Cambridge, England, United Kingdom
Head’s name
Dr Ellen Hesse
Abingdon School
Age range
11 - 18
Location
Park Road, Abingdon, Oxfordshire, OX14 1DE, United Kingdom
Head’s name
Michael Windsor
Ackworth School
Age range
2 - 18
Location
Pontefract Road, Ackworth, Pontefract, West Yorkshire, WF7 7LT, United Kingdom
Head’s name
Martyn Beer
ACS International School Cobham
Age range
3 - 18
Location
Portsmouth Road, Hersham, Cobham, KT11 1BL, United Kingdom
Head’s name
Robert Crowther
Aiglon College
Age range
9 - 18
Location
Avenue Centrale 61, 1885 Ollon, Switzerland
Head’s name
Nicola Sparrow
AIS Saigon
Age range
1 - 18
Location
264 Mai Chi Tho (East-West Highway), An Phu Ward, Thu Duc City, HCMC, Vietnam
Head’s name
Jon Standen
Akademeia High School
Age range
13 - 18
Location
Św. Urszuli Ledóchowskiej 2, 02-972 Warszawa, Poland
Head’s name
Dr Karolina Watras
AKS Lytham
Age range
0 - 18
Location
Clifton Drive South, Lytham St Annes, Lancashire, FY8 1DT, United Kingdom
Head’s name
David Harrow
Albyn School
Age range
2 - 18
Location
17-23 Queen's Road, Aberdeen, AB15 4PB, United Kingdom
Head’s name
David Starbuck
Aldenham School
Age range
0 - 18
Location
Aldenham Road, Elstree, Radlett, Borehamwood, WD6 3AJ, United Kingdom
Head’s name
Alex Hems
Alleyn’s School
Age range
4 - 18
Location
Townley Road, Dulwich, London, SE22 8SU, United Kingdom
Head’s name
Jane Lunnon
Altrincham Grammar School for Boys
Age range
Location
Marlborough Road, Bowdon, Cheshire
Head’s name
Graeme Wright
Ardingly College
Age range
2 - 18
Location
College Road, Haywards Heath, West Sussex, RH17 6SQ, United Kingdom
Head’s name
Ben Figgis
Ashford School
Age range
0 - 18
Location
East Hill, Ashford, Kent, TN24 8PB, United Kingdom
Head’s name
Michael Hall
Ashville Harrogate
Age range
2 - 18
Location
Green Lane, Harrogate, North Yorkshire, HG2 9JP, United Kingdom
Head’s name
Rhiannon Wilkinson
Badminton School
Age range
3 - 18
Location
Westbury Road, Westbury-on-Trym, Bristol, BS9 3BA, United Kingdom
Head’s name
Jessica Miles
Bancroft’s School
Age range
7 - 18
Location
High Road, Woodford Green, England, IG8 0RF, United Kingdom
Head’s name
Alex Frazer
Bangkok International Preparatory & Secondary School
Age range
3 - 18
Location
77 Sukhumvit Road, Khlong Toei Nuea, Watthana, Bangkok 10110, Thailand
Head’s name
Duncan Stonehouse
Bangor Grammar School
Age range
13 - 18
Location
Gransha Road, Bangor, County Down, Northern Ireland, BT19 7QU, United Kingdom
Head’s name
Stephen Gilmore
Barnard Castle School
Age range
4 - 18
Location
Newgate, Barnard Castle, County Durham, DL12 8UN, United Kingdom
Head’s name
David Cresswell
Bedales School
Age range
3 - 18
Location
Church Road, Petersfield, Hampshire, GU32 2DG, United Kingdom
Head’s name
Will Goldsmith
Bede’s School
Age range
13 - 18
Location
Upper Dicker, Hailsham, East Sussex, BN27 3QH, United Kingdom
Head’s name
Peter Goodyer
Bedford Modern School
Age range
7 - 18
Location
Bedford Modern School, Bedford, Bedfordshire, MK41 7NT, United Kingdom
Head’s name
David Payne
Bedford School
Age range
7 - 18
Location
De Parys Avenue, Bedford, MK40 2TU, United Kingdom
Head’s name
James Hodgson
Belfast Royal Academy
Age range
11 - 18
Location
Cliftonville Road, Belfast, Co Antrim, Northern Ireland, BT14 6JL, United Kingdom
Head’s name
Hilary Woods
Benenden School
Age range
11 - 18
Location
Cranbrook Road, Cranbrook, Kent, TN17 4AA, United Kingdom
Head’s name
Rachel Bailey
Berkhamsted School
Age range
0 - 18
Location
131 High Street, Berkhamsted, HP4 2DJ, United Kingdom
Head’s name
Richard Backhouse
Birkdale School
Age range
4 - 18
Location
4 Oakholme Road, Sheffield, South Yorkshire, S10 3DH, United Kingdom
Head’s name
Ben Bowles
Birkenhead School
Age range
0 - 18
Location
58 Beresford Road, Wirral, Merseyside, CH43 2JD, United Kingdom
Head’s name
Paul Vicars
Bishop Wordsworth’s School
Age range
11 - 18
Location
Exeter Street, Salisbury, Wiltshire, SP1 2ED, United Kingdom
Head’s name
Stuart Smallwood
Bishop’s Stortford College
Age range
4 - 18
Location
School House, Maze Green Road, Bishop's Stortford, Hertfordshire, CM23 2PQ, United Kingdom
Head’s name
John Maguire
Bloxham School
Age range
11 - 18
Location
Banbury Road, Bloxham, Banbury, Oxfordshire, OX15 4PE, United Kingdom
Head’s name
Paul Sanderson
Blundell’s School
Age range
11 - 18
Location
Blundell's Road, Tiverton, Devon, EX16 4DN, United Kingdom
Head’s name
Bart Wielenga
Bolton School
Age range
0 - 18
Location
Chorley New Road, Bolton, BL1 4PA, United Kingdom
Head’s name
Philip Britton MBE
Bootham School
Age range
3 - 18
Location
49-57 Bootham, York, YO30 7BU, United Kingdom
Head’s name
Deneal Smith