| 1 | Edge Grove School | 396 pupils | Independent · Day | Watford, East of England | — ISI · Good |
| 2 | Lochinver House School | 324 pupils | Independent · Day | Potters Bar, East of England | — ISI · Good |
| 3 | Berkhamsted Prep and Pre-Prep School | 555 pupils | Independent · Day | Berkhamsted, East of England | — |
| 4 | Alleyn Court Preparatory School | 244 pupils | Independent · Day | Southend-on-Sea, East of England | — ISI · Excellent |
| 5 | Polam School | 96 pupils | Independent · Day | Bedford, East of England | — ISI · Excellent |
| 6 | Merchant Taylors' Prep School | 365 pupils | Independent · Day | Rickmansworth, East of England | — ISI · Good |
| 7 | York House School | 360 pupils | Independent · Day | Unknown, East of England | — ISI · Good |
| 8 | Langley Preparatory School At Taverham Hall | 323 pupils | Independent · Day | Norwich, East of England | — ISI · Good |
| 9 | South Lee School | 189 pupils | Independent · Day | Bury St Edmunds, East of England | — ISI · Good |
| 10 | Manor Lodge School | 463 pupils | Independent · Day | Shenley, East of England | — ISI · Good |
| 11 | Littlegarth School | 296 pupils | Independent · Day | Colchester, East of England | — ISI · Good |
| 12 | Duncombe School | 271 pupils | Independent · Day | Hertford, East of England | — ISI · Good |
| 13 | Radlett Preparatory School Ltd | 266 pupils | Independent · Day | Herts, East of England | — ISI · Good |
| 14 | Oaklands School | 256 pupils | Independent · Day | Loughton, East of England | — ISI · Good |
| 15 | Fairstead House | 221 pupils | Independent · Day | Unknown, East of England | — ISI · Good |
| 16 | Widford Lodge School | 206 pupils | Independent · Day | Chelmsford, East of England | — ISI · Good |
| 17 | Elm Green Preparatory School | 175 pupils | Independent · Day | Essex, East of England | — ISI · Good |
| 18 | Ursuline Preparatory School | 169 pupils | Independent · Day | Brentwood, East of England | — ISI · Good |
| 19 | Maldon Court Preparatory School | 156 pupils | Independent · Day | Maldon, East of England | — ISI · Good |
| 20 | Oakwood Primary School | 153 pupils | Independent · Day | Luton, East of England | — ISI · Good |
| 21 | Loyola Preparatory School | 151 pupils | Independent · Day | BUCKHURST HILL, East of England | — ISI · Good |
| 22 | Howe Green House School | 142 pupils | Independent · Day | BISHOP'S STORTFORD, East of England | — ISI · Good |
| 23 | Hertford Prep | 137 pupils | Independent · Day | Hertford, East of England | — ISI · Good |
| 24 | Stormont School | 121 pupils | Independent · Day | Potters Bar, East of England | — ISI · Good |
| 25 | Daiglen School | 116 pupils | Independent · Day | Unknown, East of England | — ISI · Good |