EVENT 403 Mixed 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Francesca WESTON | 9 | Grantham | 2:10.00 |
| 3 | 2 | Honey FLOWER | 10 | Grantham | 1:46.00 |
| 4 | 3 | Ella KHAMA | 10 | Grantham | 1:43.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 4 | Freddie HIRST | 10 | Grantham | 1:42.41 |
| 3 | 5 | Isabelle CLAYTON | 12 | Grantham | 1:41.60 |
| 4 | 6 | Henry DOLAN | 11 | Grantham | 1:39.02 |
| 5 | 7 | Hollie-Anne CROOK | 10 | Grantham | 1:37.41 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 8 | Ava-Grace GREGORY | 12 | Grantham | 1:36.75 |
| 2 | 9 | Octavia SHEARN | 12 | Grantham | 1:35.30 |
| 3 | 10 | Violet NISBET | 13 | Grantham | 1:35.00 |
| 4 | 11 | Ruby NISBET | 10 | Grantham | 1:35.00 |
| 5 | 12 | Markas PARAPIJONAVICIU | 11 | Grantham | 1:34.30 |
| 6 | 13 | Yu Ching (Eugene) CHEU | 13 | Grantham | 1:32.77 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 14 | George LEONARD | 12 | Grantham | 1:32.25 |
| 2 | 15 | Thomas KINNEAR | 13 | Grantham | 1:32.15 |
| 3 | 16 | Leo BARNETT | 12 | Grantham | 1:32.07 |
| 4 | 17 | Mia PARAPIJONAVICIUTE | 15 | Grantham | 1:31.47 |
| 5 | 18 | Isobel ALLSOP | 14 | Grantham | 1:30.26 |
| 6 | 19 | Charlotte GILL | 16 | Grantham | 1:28.83 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 20 | Juliette KING | 12 | Grantham | 1:27.15 |
| 2 | 21 | Lucy ABBOTT | 12 | Grantham | 1:25.89 |
| 3 | 22 | Fabian KOLASA | 13 | Grantham | 1:24.48 |
| 4 | 23 | Grace HOWITT | 15 | Grantham | 1:21.16 |
| 5 | 24 | Thomas HILLSON | 11 | Grantham | 1:20.60 |
| 6 | 25 | Annabelle JAY | 13 | Grantham | 1:20.58 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 26 | Lizzy LERESCHE HANDS | 13 | Grantham | 1:19.36 |
| 2 | 27 | Amy TAYLOR | 13 | Grantham | 1:18.98 |
| 3 | 28 | Lucy WILLATTS | 13 | Grantham | 1:18.80 |
| 4 | 29 | Ben CARLYLE | 14 | Grantham | 1:17.51 |
| 5 | 30 | Sophie WARD | 15 | Grantham | 1:16.83 |
| 6 | 31 | Harriet MCCORMACK | 15 | Grantham | 1:14.70 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 32 | Emilie WEBB | 14 | Grantham | 1:14.68 |
| 2 | 33 | Ellena HOWITT | 13 | Grantham | 1:13.50 |
| 3 | 34 | Megan BROWN | 15 | Grantham | 1:09.26 |
| 4 | 35 | Evie TURNER | 18 | Grantham | 1:08.65 |
| 5 | 36 | Jack ZERAVICA | 16 | Grantham | 1:08.20 |
| 6 | 37 | Grace TURNER | 17 | Grantham | 1:07.26 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 39 | Zach HOPKINSON | 15 | Grantham | 1:05.33 |
| 2 | 41 | Jacob FISH | 15 | Grantham | 1:03.51 |
| 3 | 43 | Joshua CLARKE | 16 | Grantham | 1:00.23 |
| 4 | 42 | Owen HATHWAY | 18 | Grantham | 1:01.40 |
| 5 | 40 | Benjamin ROBERTS | 15 | Grantham | 1:03.65 |
| 6 | 38 | Daniel DEGNAN | 16 | Grantham | 1:05.52 |