EVENT 301 Female 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Jorja Atkinson | 13 | Co Cambridge | 5:24.70 |
| 4 | 3 | Ruby Chapman | 18 | Norwich Swan | 5:21.58 |
| 5 | 2 | Esmie Kidman | 18 | West Norfolk | 5:22.84 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 5 | Charlisse Harding | 15 | Norwich Swan | 5:19.19 |
| 3 | 7 | Kate Hopper | 17 | Watford SC | 5:10.93 |
| 4 | 9 | Grace Robinson | 15 | Putteridge | 5:05.70 |
| 5 | 8 | Summer Evason | 15 | Watford SC | 5:07.52 |
| 6 | 6 | Poppy Magill | 16 | Putteridge | 5:12.58 |
| 7 | 4 | Emma Cushion | 14 | Co Peterboro | 5:19.70 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Sophie Moore | 19 | Co Cambridge | 5:05.08 |
| 2 | 13 | Annie McLeod | 16 | Putteridge | 5:04.03 |
| 3 | 15 | Sadie Hunter | 16 | Co Peterboro | 5:00.67 |
| 4 | 17 | Cait Cotter | 17 | Chelmsford | 4:51.40 |
| 5 | 16 | Ruby Wheeler | 18 | Co Norwich | 4:52.05 |
| 6 | 14 | Isabelle Cameron | 17 | Co Peterboro | 5:01.28 |
| 7 | 12 | Amelia Fenner | 14 | Basildon Ph | 5:04.50 |
| 8 | 10 | Jasmine Hall | 14 | Basildon Ph | 5:05.40 |