EVENT 401 Female 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 2 | Aimee SANDERS | 12 | Dunstable | |
| 3 | 4 | Charlotte BARNARD | 13 | Camden Swiss | 6:31.47 |
| 4 | 6 | Carmen BISS | 13 | Camden Swiss | 6:20.58 |
| 5 | 5 | Zara CHAMORRO | 15 | Camden Swiss | 6:23.01 |
| 6 | 3 | Matilda TOMKINSON | 11 | Co Milton K | |
| 7 | 1 | Emily BRATILESCU | 11 | Newport Pag | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 9 | Olivia COOPER | 15 | Dunstable | 6:00.60 |
| 2 | 11 | Amelia DONNELLY | 12 | Camden Swiss | 5:54.60 |
| 3 | 13 | Isla PIPER | 13 | Co Milton K | 5:48.18 |
| 4 | 15 | Maya AL FAISAL | 15 | Camden Swiss | 5:38.63 |
| 5 | 14 | Keira OSORIO | 15 | Camden Swiss | 5:39.82 |
| 6 | 12 | Ashley-Jane ANG | 12 | Camden Swiss | 5:54.00 |
| 7 | 10 | Alice BUCKINGHAM | 11 | Team Luton | 5:57.00 |
| 8 | 7 | Ayla THIEDE | 12 | Camden Swiss | 6:11.00 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Jemima DA SILVA | 13 | Camden Swiss | 5:32.70 |
| 2 | 21 | Emma TOOLEY | 14 | Co Milton K | 5:28.08 |
| 3 | 23 | Elliana ZOBEL | 14 | Camden Swiss | 5:25.60 |
| 4 | 25 | Linnoa HURCOMBE | 13 | Camden Swiss | 5:19.10 |
| 5 | 24 | Eleanor PORTER | 13 | Camden Swiss | 5:20.70 |
| 6 | 22 | Nina MORII | 13 | Camden Swiss | 5:26.87 |
| 7 | 19 | Poppy MORRIS | 13 | Co Milton K | 5:31.01 |
| 8 | 16 | Eva CHAMORRO | 13 | Camden Swiss | 5:36.48 |