EVENT 401 Womens Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 2 | 2 | Ella Bainbridge | 15 | Donc Dartes | 4:57.31 |
| 3 | 4 | Natalie Sanford | 15 | St Felix Sch | 4:56.58 |
| 4 | 6 | Chloe Hirst | 16 | Bo Kirklees | 4:55.95 |
| 5 | 5 | Kate Morris | 14 | Nova Cent'n | 4:56.05 |
| 6 | 3 | Martha Hurst | 15 | Stockport Mo | 4:56.83 |
| 7 | 1 | Annabelle Wilkinson | 14 | Co Sheffield | 4:57.52 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 8 | Rachel Hornby | 15 | Wigan BEST | 4:55.90 |
| 1 | 10 | Lara Thomson | 14 | Co Leeds | 4:55.22 |
| 2 | 12 | Carys O'Reilly | 16 | Co Leicester | 4:54.85 |
| 3 | 14 | Emma Erskine | 15 | Nova Cent'n | 4:54.51 |
| 4 | 16 | Abigail Lacey | 17 | Portsmouth N | 4:54.33 |
| 5 | 15 | Molly Francis | 18 | Loughboro Un | 4:54.44 |
| 6 | 13 | Charlotte Rigg | 17 | Co Birm'ham | 4:54.76 |
| 7 | 11 | Anna Marley | 18 | Harrogate | 4:55.14 |
| 8 | 9 | Kidiest Hodgson | 15 | Co Leeds | 4:55.33 |
| 9 | 7 | Ellie Sibbald-Perkins | 15 | Co Birm'ham | 4:55.92 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 19 | Amy Corcoran | 17 | KingstonHull | 4:52.93 |
| 1 | 23 | Polly Painter | 17 | Millfield | 4:51.88 |
| 2 | 27 | Olivia Clare | 16 | Co Manch Aq | 4:49.79 |
| 3 | 31 | Amelia Monaghan | 17 | Co Peterboro | 4:45.03 |
| 4 | 35 | Lily Booker | 18 | Millfield | 4:39.78 |
| 5 | 33 | Amber Keegan | 22 | Co Sheffield | 4:44.42 |
| 6 | 29 | Alice Dearing | 22 | Loughboro Un | 4:47.67 |
| 7 | 25 | Olivia Herron | 15 | Stockport Mo | 4:51.51 |
| 8 | 21 | Isabelle Goodwin | 15 | Co Leeds | 4:52.58 |
| 9 | 17 | Ellie Wheeler | 17 | Basildon Ph | 4:53.77 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 20 | Lana Broekhoven | 16 | Plymouth Lea | 4:52.60 |
| 1 | 24 | Maisie Thornton | 16 | Crawley | 4:51.63 |
| 2 | 28 | Erin Davies | 16 | Co Birm'ham | 4:49.46 |
| 3 | 32 | Sophia Wilson | 18 | Millfield | 4:45.00 |
| 4 | 36 | Freya Colbert | 15 | Nova Cent'n | 4:39.11 |
| 5 | 34 | Michaella Glenister | 17 | Leic Sharks | 4:42.44 |
| 6 | 30 | Caitlin Mackay | 18 | Wycombe Dist | 4:46.96 |
| 7 | 26 | Rachel Anderson | 17 | Millfield | 4:51.03 |
| 8 | 22 | Abigail Miles | 15 | Co Sheffield | 4:51.92 |
| 9 | 18 | Libby Freeman | 13 | Morpeth | 4:53.69 |