EVENT 524 Women 16 Yrs/Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 2 | 2 | Eliza Humphrey | 18 | S11 | Northampton | 5:49.63 |
| 3 | 4 | Ashley Jones | 17 | | Wellingboro | 5:43.72 |
| 4 | 6 | Isabel Hollyman | 18 | | Wellingboro | 5:31.12 |
| 5 | 5 | Grace Williams | 18 | | Nene Valley | 5:37.80 |
| 6 | 3 | Scarlett Humphrey | 18 | S11 | Northampton | 5:47.60 |
| 7 | 1 | Ruby Cummins | 18 | | Wellingboro | 5:54.41 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 8 | Bryony Cook | 16 | | Rushden | 5:07.00 |
| 2 | 10 | Amber Haycock | 16 | S10 | Rushden | 5:02.54 |
| 3 | 12 | Orla Eyton-Jones | 17 | | Corby | 4:59.13 |
| 4 | 14 | Sarah Hollis | 35 | | Northampton | 4:49.74 |
| 5 | 13 | Kalinika Cwiklinska | 16 | | Northampton | 4:53.60 |
| 6 | 11 | Harriet Casey | 17 | | Corby | 5:02.10 |
| 7 | 9 | Summer York | 17 | | Corby | 5:04.00 |
| 8 | 7 | Maisie Summers-Newton | 21 | S6 | Northampton | 5:20.10 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 16 | Mia Matthews | 16 | | Northampton | 4:48.10 |
| 2 | 18 | Anna Johnson | 18 | | Northampton | 4:43.30 |
| 3 | 20 | Elise Sophia Kendall | 17 | | Corby | 4:37.23 |
| 4 | 22 | Lily Freeman | 16 | | Northampton | 4:29.60 |
| 5 | 21 | Emilia Cieszczyk | 16 | | Northampton | 4:33.60 |
| 6 | 19 | Lilly Tappern | 16 | | Corby | 4:42.20 |
| 7 | 17 | Grace Wingham | 16 | | Kettering | 4:48.01 |
| 8 | 15 | Lea Bromwich | 17 | | Corby | 4:49.16 |