EVENT 401 Female 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Rosie CLEMENTS | 11 | Wisbech | 8:18.48 |
| 4 | 3 | Keitija LEONOVA | 12 | Wisbech | 7:55.23 |
| 5 | 2 | Emma CHAMBERLAIN | 12 | Wellingboro | 8:07.20 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 5 | Maisie BISHOP | 12 | Wisbech | 7:05.14 |
| 3 | 7 | Nicola JAMES | 53 | Market Har | 6:32.80 |
| 4 | 9 | Holly SMITH | 13 | Wisbech | 6:17.60 |
| 5 | 8 | Millie DAY | 17 | Wellingboro | 6:31.40 |
| 6 | 6 | Emma AFFLECK | 14 | Kettering | 6:34.40 |
| 7 | 4 | Arabella TYSTERMAN | 11 | Wisbech | 7:05.94 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Aaliyah BEETSON | 16 | Wellingboro | 6:02.30 |
| 2 | 13 | Faye EYTON-JONES | 16 | Corby | 5:59.33 |
| 3 | 15 | Elisa GIRAUD | 13 | Corby | 5:37.50 |
| 4 | 17 | Lilly TAPPERN | 18 | Corby | 5:10.40 |
| 5 | 16 | Lauren MORLEY | 16 | Kettering | 5:36.00 |
| 6 | 14 | Eva GALLAGHER | 16 | Corby | 5:51.30 |
| 7 | 12 | Isabella BURTON | 16 | Wisbech | 6:00.70 |
| 8 | 10 | Georgia SMITH | 16 | Corby | 6:10.20 |