EVENT 301 Female 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 2 | Lola MALCOLM | 9 | Co Leeds | 8:10.00 |
| 3 | 4 | Stella BOWES | 9 | Co Leeds | 8:03.40 |
| 4 | 6 | Lily HOGAN | 9 | Co Leeds | 7:31.46 |
| 5 | 5 | Hannah CROFTON | 10 | Co Leeds | 7:41.06 |
| 6 | 3 | Matilda DARK | 10 | Co Leeds | 8:10.00 |
| 7 | 1 | Matilda PENNELLS | 10 | Co Leeds | 8:10.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 8 | Isabella HUTCHISON | 10 | Co Leeds | 7:12.10 |
| 1 | 10 | Qian SHEN | 11 | Co Leeds | 6:58.94 |
| 2 | 12 | Ayla CARRY | 11 | Co Leeds | 6:48.70 |
| 3 | 14 | Elizabeth ROTHWELL | 11 | Co Leeds | 6:45.00 |
| 4 | 16 | Esmie WILES | 12 | Warrington W | 6:24.50 |
| 5 | 15 | Sophia WEEKS | 12 | Co Leeds | 6:29.69 |
| 6 | 13 | Francesca SPALDING | 11 | Co Leeds | 6:45.00 |
| 7 | 11 | Martha NEWMAN | 10 | Co Leeds | 6:49.40 |
| 8 | 9 | Matilda SHERLEY-PRICE | 9 | Co Leeds | 7:00.00 |
| 9 | 7 | Sophia Xiu Hui KOK | 11 | Co Leeds | 7:29.86 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 18 | Evie THORPE | 13 | Co Leeds | 6:18.72 |
| 1 | 20 | Evie MORAN | 12 | Co Leeds | 6:13.80 |
| 2 | 22 | Verity LILLEY | 12 | Co Leeds | 6:01.80 |
| 3 | 24 | Isabelle PARK | 11 | Co Leeds | 6:00.27 |
| 4 | 26 | Jessica GRAY-THOMAS | 11 | Conwy | 5:58.19 |
| 5 | 25 | Amelia SYNOWIEC | 14 | Conwy | 5:59.27 |
| 6 | 23 | Livia STACEY | 13 | Co Leeds | 6:01.00 |
| 7 | 21 | Amelia MATSON | 13 | Co Leeds | 6:04.60 |
| 8 | 19 | Kiera WILLIAMS | 14 | Conwy | 6:14.00 |
| 9 | 17 | Libby HOWARD | 13 | Warrington W | 6:20.00 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 28 | Zoe FEATHER | 12 | Co Leeds | 5:57.16 |
| 1 | 30 | Neve STAFFORD | 12 | Co Leeds | 5:51.28 |
| 2 | 32 | Madeline BECKRAM | 12 | Co Leeds | 5:50.94 |
| 3 | 34 | Isla PERRY | 11 | Warrington W | 5:47.10 |
| 4 | 36 | Jessica JONES | 15 | Warrington W | 5:13.20 |
| 5 | 35 | Chloe JOBSON | 12 | South Tyne | 5:45.46 |
| 6 | 33 | Pippa BROTHERTON | 11 | South Tyne | 5:49.27 |
| 7 | 31 | Juliette CONNOLLY | 14 | Conwy | 5:51.20 |
| 8 | 29 | Daisy TOMKINSON | 14 | Aquabears | 5:54.90 |
| 9 | 27 | Evelyn ATKINSON | 11 | Co Leeds | 5:57.31 |