EVENT 401 Mixed 200m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Gracie PAYNE | 12 | Grantham | 4:00.00 |
| 3 | 2 | Juliette KIM | 10 | Grantham | 3:50.00 |
| 4 | 3 | Emmeline GLEAVE | 10 | Grantham | 3:50.00 |
| 5 | 4 | Yu Ching (Eugene) CHEU | 14 | Grantham | 3:38.27 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Henry DOLAN | 12 | Grantham | 3:35.00 |
| 2 | 6 | Isabelle CLAYTON | 13 | Grantham | 3:31.22 |
| 3 | 7 | Freddie HIRST | 11 | Grantham | 3:30.00 |
| 4 | 8 | Hollie-Ann CROOK | 11 | Grantham | 3:29.97 |
| 5 | 9 | Octavia SHEARN | 13 | Grantham | 3:25.00 |
| 6 | 10 | Thomas KINNEAR | 14 | Grantham | 3:18.62 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Lucy ABBOTT | 13 | Grantham | 3:17.75 |
| 2 | 12 | Joshua KIM | 13 | Grantham | 3:04.60 |
| 3 | 13 | George LEONARD | 13 | Grantham | 3:01.21 |
| 4 | 14 | Leo BARNETT | 13 | Grantham | 3:01.18 |
| 5 | 15 | Amy TAYLOR | 14 | Grantham | 2:58.90 |
| 6 | 16 | Ellena HOWITT | 14 | Grantham | 2:55.55 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Lucy WILLATTS | 14 | Grantham | 2:44.63 |
| 2 | 20 | Zach HOPKINSON | 16 | Grantham | 2:26.27 |
| 3 | 22 | Grace TURNER | 18 | Grantham | 2:24.16 |
| 4 | 21 | Ben CARLYLE | 15 | Grantham | 2:24.39 |
| 5 | 19 | Chloe HOPKINSON | 20 | Grantham | 2:30.70 |
| 6 | 17 | Thomas HILLSON | 12 | Grantham | 2:47.51 |