EVENT 104 Womens Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 3 | 1 | Iona Macleod | 14 | Dun City Aqu | 5:05.17 |
| 4 | 3 | Erin Davies | 14 | Co Birm'ham | 5:05.04 |
| 5 | 2 | Katie Taylor | 17 | Heart Of Mid | 5:05.04 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 5 | Gaia Alcaras | 15 | Aberdeen Per | 5:04.17 |
| 2 | 7 | Eleanor Cowan | 15 | Wycombe Dist | 5:03.89 |
| 3 | 9 | Lily Booker | 16 | Co Bristol | 5:03.20 |
| 4 | 11 | Ellinor Southward | 16 | Ellesmere Co | 5:03.03 |
| 5 | 10 | Elizabeth Kingham | 15 | Co Birm'ham | 5:03.19 |
| 6 | 8 | Keanna Macinnes | 16 | Heart Of Mid | 5:03.63 |
| 7 | 6 | Ellie Wheeler | 15 | Basildon Ph | 5:04.01 |
| 8 | 4 | Phoebe Griffiths | 17 | Ellesmere Co | 5:04.95 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 13 | Rebecca Fisher | 16 | Co Leeds | 5:02.55 |
| 2 | 15 | Olivia Tatton | 17 | Northampton | 5:02.50 |
| 3 | 17 | Michaella Glenister | 15 | Co Leicester | 5:02.35 |
| 4 | 19 | Meghan Byrne | 17 | Barnet Copt | 5:01.58 |
| 5 | 18 | Megan Sheard | 16 | Stockport Mo | 5:02.33 |
| 6 | 16 | Kiera Henley | 16 | Stockport Mo | 5:02.46 |
| 7 | 14 | Amelia Monaghan | 15 | Co Peterboro | 5:02.55 |
| 8 | 12 | Caitlin Mackay | 16 | Wycombe Dist | 5:02.71 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 21 | Madelaine Hardingham | 14 | Newcastle | 5:01.11 |
| 2 | 23 | Keelan Fitton | 17 | Bo Kirklees | 5:00.85 |
| 3 | 25 | Daisy Anderson | 16 | Thanet Swim | 5:00.23 |
| 4 | 27 | Rachel Anderson | 15 | Millfield | 4:59.72 |
| 5 | 26 | Tori Sopp | 17 | Wirral Metro | 4:59.80 |
| 6 | 24 | Alexandra Bartley | 15 | Co Birm'ham | 5:00.55 |
| 7 | 22 | Martyna Ruszkowska | 16 | Swim Gwynedd | 5:01.11 |
| 8 | 20 | Rebecca Clynes | 15 | Co Leeds | 5:01.37 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 29 | Mollie Wright | 19 | Nova Cent'n | 4:58.59 |
| 2 | 31 | Rosanna Arnold | 17 | Thanet Swim | 4:58.33 |
| 3 | 33 | Olivia Gardner | 19 | Ellesmere Co | 4:57.01 |
| 4 | 35 | Chanel Sneddon | 18 | F.I.R.S.T. | 4:55.73 |
| 5 | 34 | Tia Ward | 14 | Co Leeds | 4:56.62 |
| 6 | 32 | Alicia Wilson | 17 | Guildford Ct | 4:57.93 |
| 7 | 30 | Rebecca Sutton | 16 | Bridgend Cty | 4:58.42 |
| 8 | 28 | Jessica Thomson | 18 | Aberdeen Per | 4:58.95 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 38 | Ciara Schlosshan | 16 | Co Leeds | 4:54.67 |
| 2 | 42 | Amy Bell | 17 | Co Sheffield | 4:51.64 |
| 3 | 46 | Amber Keegan | 20 | Co Sheffield | 4:47.34 |
| 4 | 50 | Aimee Willmott | 24 | London Aquat | 4:34.08 |
| 5 | 48 | Rosie Rudin | 19 | Co Sheffield | 4:44.31 |
| 6 | 44 | Emily Large | 16 | Newcastle | 4:49.16 |
| 7 | 40 | Sophia Wilson | 16 | Millfield | 4:53.89 |
| 8 | 36 | Melanie Hall | 18 | Royal Wolv | 4:55.59 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 39 | Niamh McDonagh | 18 | Bo Stockton | 4:54.63 |
| 2 | 43 | Orla Adams | 22 | Aberdeen Per | 4:50.86 |
| 3 | 47 | Constance Dean | 19 | Maidenhead | 4:45.46 |
| 4 | 51 | Hannah Miley | 28 | Aberdeen Per | 4:32.54 |
| 5 | 49 | Abbie Wood | 18 | Loughboro Un | 4:40.38 |
| 6 | 45 | Lucy McKenzie | 20 | Stockport Mo | 4:47.80 |
| 7 | 41 | Emily Siebrecht | 20 | Bath Univ | 4:52.62 |
| 8 | 37 | Tara Haworth | 18 | Lincoln Vulc | 4:54.79 |