EVENT 301 Female 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Isobel HARRISON | 10 | Co Sheffield | 8:30.00 |
| 4 | 3 | Sophia LANGE | 9 | Co Leeds | 7:20.00 |
| 5 | 2 | Anissia Ioana TILEA | 10 | Co Sheffield | 8:30.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Qian SHEN | 10 | Co Leeds | 7:10.00 |
| 2 | 7 | Madeleine FLAHERTY | 10 | Co Leeds | 7:08.80 |
| 3 | 9 | Alana RANKIN | 10 | Co Leeds | 7:00.00 |
| 4 | 11 | Alexia WASTAKARAN | 12 | Co Sheffield | 6:45.00 |
| 5 | 10 | Isla CUNDILL | 10 | Co Leeds | 6:53.20 |
| 6 | 8 | Katie SADLER | 10 | Co Leeds | 7:04.00 |
| 7 | 6 | Grace OLDHAM | 11 | Co Leeds | 7:10.00 |
| 8 | 4 | Evie COOK | 11 | Co Leeds | 7:13.12 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 13 | Evie THORPE | 12 | Co Leeds | 6:40.21 |
| 2 | 15 | Betsy KIRKLEY | 11 | Co Leeds | 6:30.75 |
| 3 | 17 | Sophia GRAVILLE | 12 | Co Leeds | 6:23.60 |
| 4 | 19 | Neve STAFFORD | 11 | Co Leeds | 6:14.03 |
| 5 | 18 | Amelia SYNOWIEC | 13 | Conwy | 6:17.20 |
| 6 | 16 | Prudence PEARSON | 9 | Co Sheffield | 6:30.00 |
| 7 | 14 | Verity LILLEY | 11 | Co Leeds | 6:37.97 |
| 8 | 12 | Hannah INAYAT | 13 | Co Sheffield | 6:44.30 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 22 | Eva SYLVESTER | 12 | Co Leeds | 6:06.37 |
| 2 | 24 | Emily MARRISON | 14 | Co Leeds | 5:56.80 |
| 3 | 26 | Jessica ROLLINGS | 12 | Co Leeds | 5:46.07 |
| 4 | 28 | Erin BENTLEY | 13 | Co Leeds | 5:38.03 |
| 5 | 27 | Serenity THOMAS | 13 | Conwy | 5:40.00 |
| 6 | 25 | Annabel GALBRAITH | 13 | Co Leeds | 5:46.50 |
| 7 | 23 | Elizabeth BOND | 12 | Co Leeds | 5:59.36 |
| 8 | 20 | Isla STOCKLEY | 12 | Co Sheffield | 6:07.00 |