EVENT 301 Womens Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 2 | Olivia Molden | 14 | Stockport Mo | 5:02.93 |
| 1 | 4 | Lara Thomson | 13 | Co Leeds | 5:02.23 |
| 2 | 6 | Ella Cooper | 14 | Co Leeds | 5:01.83 |
| 3 | 8 | Merissa Booth | 13 | Wycombe Dist | 5:01.67 |
| 4 | 10 | Lily Merrett | 15 | Co St Albans | 5:01.19 |
| 5 | 9 | Kidiest Hodgson | 14 | Co Leeds | 5:01.43 |
| 6 | 7 | Jennifer Green | 15 | Wigan BEST | 5:01.68 |
| 7 | 5 | Grace King | 15 | teamipswich | 5:02.22 |
| 8 | 3 | Libby Freeman | 12 | Morpeth | 5:02.69 |
| 9 | 1 | Rachel Hornby | 14 | Wigan BEST | 5:03.12 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 12 | Maisie Thornton | 15 | Brighton | 5:00.69 |
| 1 | 14 | Emma Erskine | 14 | Nova Cent'n | 5:00.43 |
| 2 | 16 | Erin O'Meara | 15 | Watford SC | 4:59.90 |
| 3 | 18 | Amy Brown | 14 | S Bournem'th | 4:59.65 |
| 4 | 20 | Chloe Hirst | 15 | Bo Kirklees | 4:58.38 |
| 5 | 19 | Martha Hurst | 14 | Stockport Mo | 4:59.32 |
| 6 | 17 | Martha Bradley | 14 | Co Leeds | 4:59.66 |
| 7 | 15 | Issey-May Reeves | 14 | Co Sheffield | 5:00.15 |
| 8 | 13 | Lucie Peck | 15 | West Norfolk | 5:00.63 |
| 9 | 11 | Rachel Cornford | 15 | Wycombe Dist | 5:00.85 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 22 | Millie Checkley | 14 | Co Birm'ham | 4:58.21 |
| 1 | 24 | Sophie Freeman | 14 | Plymouth Lea | 4:57.34 |
| 2 | 26 | Isabelle Goodwin | 14 | Co Leeds | 4:56.56 |
| 3 | 28 | Anna Marley | 17 | Harrogate | 4:55.14 |
| 4 | 30 | Ellie Wheeler | 16 | Basildon Ph | 4:54.90 |
| 5 | 29 | Olivia Clare | 15 | Co Manch Aq | 4:55.05 |
| 6 | 27 | Amy Corcoran | 16 | KingstonHull | 4:55.27 |
| 7 | 25 | Rose Compton | 15 | RTW Monson | 4:57.20 |
| 8 | 23 | Erin Hoyland | 15 | Co Manch Aq | 4:57.88 |
| 9 | 21 | Livia Kingsland | 13 | Nova Cent'n | 4:58.35 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 32 | Erin Davies | 15 | Co Birm'ham | 4:54.78 |
| 1 | 34 | Molly Francis | 17 | Mt Kelly | 4:54.44 |
| 2 | 36 | Tilly Hansen-Hamilton | 16 | Guildford Ct | 4:53.30 |
| 3 | 38 | Elizabeth Kingham | 16 | Co Birm'ham | 4:52.66 |
| 4 | 40 | Rose Foden | 19 | Bath Univ | 4:52.56 |
| 5 | 39 | Sophie Barker | 17 | Co Sheffield | 4:52.65 |
| 6 | 37 | Melanie Hall | 19 | Co Sheffield | 4:52.96 |
| 7 | 35 | Charlotte Robinson | 15 | Co Leeds | 4:53.35 |
| 8 | 33 | Beatrice Varley | 15 | Hamilton UAE | 4:54.73 |
| 9 | 31 | Olivia Butler | 15 | Co Bristol | 4:54.81 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 43 | Meghan Byrne | 18 | Barnet Copt | 4:52.17 |
| 1 | 47 | Mia Leech | 16 | Co Peterboro | 4:51.53 |
| 2 | 51 | Freya Colbert | 14 | Nova Cent'n | 4:45.62 |
| 3 | 55 | Emilia Sansome | 17 | Wycombe Dist | 4:44.46 |
| 4 | 59 | Amy Bell | 18 | Co Sheffield | 4:39.49 |
| 5 | 57 | Laura Stephens | 19 | Plymouth Lea | 4:43.42 |
| 6 | 53 | Daisy Anderson | 17 | Thanet Swim | 4:44.79 |
| 7 | 49 | Amelia Monaghan | 16 | Co Peterboro | 4:49.21 |
| 8 | 45 | Polly Painter | 16 | Millfield | 4:51.88 |
| 9 | 41 | Rachel Anderson | 16 | Millfield | 4:52.42 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 44 | Abigail Miles | 14 | Co Sheffield | 4:51.92 |
| 1 | 48 | Caitlin Mackay | 17 | Wycombe Dist | 4:49.80 |
| 2 | 52 | Tori Sopp | 18 | Wirral Metro | 4:45.18 |
| 3 | 56 | Michaella Glenister | 16 | Leic Sharks | 4:44.22 |
| 4 | 60 | Abbie Wood | 19 | Loughboro Un | 4:34.55 |
| 5 | 58 | Ally Larson | 18 | Camden Swiss | 4:42.44 |
| 6 | 54 | Sophia Wilson | 17 | Millfield | 4:44.77 |
| 7 | 50 | Mollie Wright | 20 | Nova Cent'n | 4:46.51 |
| 8 | 46 | Eleanor Morris | 19 | Birm'ham Uni | 4:51.86 |
| 9 | 42 | Ailsa McDonald | 17 | Northampton | 4:52.32 |