EVENT 402 Female 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Lilly SMITH | 12 | Haringey | |
| 4 | 3 | Merryn AVERY | 12 | Linslade | |
| 5 | 2 | Annabel WHETTON | 10 | Harpenden | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 4 | Isla MCDONNELL | 15 | Harpenden | |
| 2 | 6 | Ruth BISCOE | 10 | Team Luton | |
| 3 | 10 | Inaaya SAMPONG | 11 | Team Luton | |
| 4 | 12 | Josephine BROWN | 10 | Linslade | |
| 5 | 11 | Chloe MATTHEWS | 12 | Linslade | |
| 6 | 9 | Ines PUENTE | 12 | Haringey | |
| 7 | 5 | Sophie GARLAND | 11 | Harpenden | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 14 | Cora PAYNE | 9 | Bletchley | 6:42.60 |
| 2 | 16 | Rahil ABWOOLI | 10 | TigersJersey | 6:28.90 |
| 3 | 20 | Orla LELAI | 11 | TigersJersey | 6:14.60 |
| 4 | 22 | Ava HOWARD | 14 | Team Luton | 5:57.41 |
| 5 | 21 | Suji WEE | 12 | Watford SC | 6:02.60 |
| 6 | 17 | Isabelle WORSFOLD | 16 | Linslade | 6:27.10 |
| 7 | 15 | Annabelle CLARK | 12 | Harpenden | 6:34.17 |
| 8 | 13 | Amélie DESMEULES | 10 | Verulam | |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 24 | Adel TONKO | 11 | TigersJersey | 5:55.40 |
| 2 | 26 | Harriet SEDGWICK | 12 | New Hall | 5:49.50 |
| 3 | 28 | Ella BAKER | 11 | TigersJersey | 5:47.40 |
| 4 | 30 | Lauren TOUGH | 13 | Team Luton | 5:45.60 |
| 5 | 29 | Kaylyn SAMPONG | 13 | Team Luton | 5:46.70 |
| 6 | 27 | Clara LEON | 12 | Team Luton | 5:48.60 |
| 7 | 25 | Elizabeth STOCKS | 11 | Linslade | 5:51.60 |
| 8 | 23 | Hailey Hong Yuen LEUNG | 13 | Harpenden | 5:56.30 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 32 | Coral TURNER | 13 | Biggleswade | 5:41.05 |
| 2 | 35 | Elizabeth STEVENSON | 15 | Biggleswade | 5:30.80 |
| 3 | 37 | Mia LOVESEY | 17 | Biggleswade | 5:23.20 |
| 4 | 39 | Ella PRUCE | 13 | Team Luton | 5:21.40 |
| 5 | 38 | Emily CALVERT | 13 | Team Luton | 5:21.96 |
| 6 | 36 | Eliza JENNINGS | 12 | Biggleswade | 5:29.96 |
| 7 | 34 | Victoria GRANT | 10 | TigersJersey | 5:31.10 |
| 8 | 31 | Caitlin PETERS | 15 | Harpenden | 5:42.90 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 41 | Lydia WARD | 15 | Newport Pag | 5:18.77 |
| 2 | 43 | AMY HARRIS | 13 | Broomfield | 5:13.20 |
| 3 | 45 | Niamh CHURCH | 12 | TigersJersey | 5:07.60 |
| 4 | 47 | Nicole CASHIN | 14 | Team Luton | 5:05.20 |
| 5 | 46 | Selina GREEN | 14 | New Hall | 5:05.60 |
| 6 | 44 | Emilie HIGGS | 14 | Newport Pag | 5:08.34 |
| 7 | 42 | Clara FOSTER | 17 | Linslade | 5:16.34 |
| 8 | 40 | Tara SHAH | 13 | Bushey | 5:21.00 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 49 | Matilda HANNAM | 12 | Newport Pag | 5:03.10 |
| 2 | 51 | Summer EVASON | 14 | Watford SC | 4:56.30 |
| 3 | 53 | Eveline GAYDON | 15 | Colchester | 4:46.00 |
| 4 | 55 | Matilda BOGLE | 18 | teamipswich | 4:25.61 |
| 5 | 54 | Cailin HEHIR | 15 | Watford SC | 4:39.00 |
| 6 | 52 | ORLAGH QUARRELL | 13 | Broomfield | 4:48.50 |
| 7 | 50 | Jemima KIMBER | 16 | Linslade | 4:59.30 |
| 8 | 48 | Heather ELRICK | 15 | Newport Pag | 5:04.40 |