EVENT 304 Mixed 200m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Olivia CHARITY | 12 | Grantham | 3:58.00 |
| 2 | 2 | Joshua KIM | 12 | Grantham | 3:57.90 |
| 3 | 3 | Amy TAYLOR | 13 | Grantham | 3:47.38 |
| 4 | 4 | Lucy ABBOTT | 12 | Grantham | 3:35.45 |
| 5 | 5 | Leo BARNETT | 12 | Grantham | 3:27.92 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 6 | George LEONARD | 12 | Grantham | 3:27.21 |
| 2 | 7 | Thomas KINNEAR | 13 | Grantham | 3:24.84 |
| 3 | 8 | Fabian KOLASA | 13 | Grantham | 3:20.56 |
| 4 | 9 | Thomas HILLSON | 11 | Grantham | 3:17.63 |
| 5 | 10 | Lucy WILLATTS | 13 | Grantham | 3:08.74 |
| 6 | 11 | Ben CARLYLE | 14 | Grantham | 3:08.57 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 12 | Emilie WEBB | 14 | Grantham | 3:06.15 |
| 2 | 13 | Grace HOWITT | 15 | Grantham | 3:03.73 |
| 3 | 14 | Ellena HOWITT | 13 | Grantham | 2:55.59 |
| 4 | 15 | Sophie WARD | 15 | Grantham | 2:51.69 |
| 5 | 16 | Harriet MCCORMACK | 15 | Grantham | 2:47.88 |
| 6 | 17 | Megan BROWN | 15 | Grantham | 2:35.80 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Daniel DEGNAN | 16 | Grantham | 2:26.89 |
| 2 | 21 | Jacob FISH | 15 | Grantham | 2:19.71 |
| 3 | 23 | Joshua CLARKE | 16 | Grantham | 2:00.00 |
| 4 | 22 | Owen HATHWAY | 18 | Grantham | 2:15.00 |
| 5 | 20 | Grace TURNER | 17 | Grantham | 2:26.60 |
| 6 | 18 | Zach HOPKINSON | 15 | Grantham | 2:34.76 |