EVENT 223 Women Open 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 2 | Lily Herring | 14 | S10 | Norwich Swan | 6:13.93 |
| 2 | 4 | Lyla Howard | 15 | | Team Luton | 4:48.07 |
| 3 | 6 | Connie Davies | 16 | | Deben | 4:46.85 |
| 4 | 8 | Niamh O'Meara | 16 | | Watford SC | 4:45.90 |
| 5 | 7 | Aislin Foley-Wright | 15 | | Basildon Ph | 4:46.08 |
| 6 | 5 | Natalie Taylor | 15 | | St Felix Sch | 4:47.78 |
| 7 | 3 | Abigail Wickens | 15 | S8 | Flitwick | 6:04.60 |
| 8 | 1 | Helen Thompson | 19 | S14 | Colchester | 6:47.40 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 10 | Bryony Edgings | 17 | | Thurrock | 4:43.89 |
| 2 | 12 | Grace Greenhalf | 15 | | Co Norwich | 4:42.20 |
| 3 | 14 | Francesca Key | 17 | | Thurrock | 4:41.71 |
| 4 | 16 | Olivia Church | 16 | | Thurrock | 4:41.23 |
| 5 | 15 | Kirsty Neill | 15 | | Bishop Stort | 4:41.68 |
| 6 | 13 | Camille Vannier | 15 | | Hatfield | 4:42.08 |
| 7 | 11 | Indy Scott | 17 | | Co Cambridge | 4:43.48 |
| 8 | 9 | Lexie Goodman | 15 | | Basildon Ph | 4:44.50 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 18 | Romilly Marks | 16 | | Newmarket | 4:40.01 |
| 2 | 20 | Gabriela Gomez Pavon | 15 | | Potters Bar | 4:38.39 |
| 3 | 22 | Olivia Fletcher | 19 | | Basildon Ph | 4:38.29 |
| 4 | 24 | Gracie Comitti | 15 | | Basildon Ph | 4:36.33 |
| 5 | 23 | Charlotte Tree | 18 | | Colchester | 4:37.98 |
| 6 | 21 | Holly Driver | 17 | | St Felix Sch | 4:38.38 |
| 7 | 19 | Meisha Trend-Evans | 16 | | Bishop Stort | 4:39.41 |
| 8 | 17 | Lisa Leinemann | 15 | | Chelmsford | 4:40.82 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 26 | Lucy Young | 17 | | Modernian | 4:35.38 |
| 2 | 28 | Sophie Dowding | 15 | | teamipswich | 4:32.92 |
| 3 | 30 | Millie Fields | 18 | | Bishop Stort | 4:32.10 |
| 4 | 32 | Skye Carter | 15 | | Basildon Ph | 4:30.62 |
| 5 | 31 | Francesca Baber | 16 | | Flitwick | 4:32.02 |
| 6 | 29 | Alexa Mann | 16 | | Chelmsford | 4:32.89 |
| 7 | 27 | Erin Wilkinson | 17 | | Basildon Ph | 4:33.60 |
| 8 | 25 | Anna-Lucia Fenner | 16 | | Basildon Ph | 4:35.93 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 34 | Jessica-Jane Applegate | 26 | S14 | Co Norwich | 4:30.00 |
| 2 | 36 | Adel Zakrzewski | 19 | | Co Norwich | 4:29.50 |
| 3 | 38 | Sacha Thomas | 19 | | Co Norwich | 4:27.90 |
| 4 | 40 | Harriet Salisbury | 18 | | Co Peterboro | 4:23.40 |
| 5 | 39 | Holly Lamb | 17 | | Basildon Ph | 4:26.40 |
| 6 | 37 | Karys-Rose Bunn | 16 | | teamipswich | 4:28.71 |
| 7 | 35 | Cait Cotter | 15 | | Chelmsford | 4:29.73 |
| 8 | 33 | Madelyn Latimer-Hicks | 18 | | St Felix Sch | 4:30.19 |