EVENT 303 Mixed 100m Backstroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Henry LEONARD | 9 | Grantham | |
| 2 | 2 | Sophia WRIGHT | 9 | Grantham | |
| 3 | 3 | Albert THORPE | 11 | Grantham | |
| 4 | 4 | Tilly WASKETT-BOOTH | 9 | Grantham | |
| 5 | 5 | George DOLAN | 9 | Grantham | |
| 6 | 6 | Matilda HARPER | 9 | Grantham | 2:20.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 7 | Bethany MEAKIN | 11 | Grantham | 2:00.00 |
| 2 | 8 | Georgia BELLETT | 10 | Grantham | 2:00.00 |
| 3 | 9 | Evie FELTON | 10 | Grantham | 2:00.00 |
| 4 | 10 | Hannah EXLEY | 11 | Grantham | 2:00.00 |
| 5 | 11 | Yu Tsing (Trixie) CHEU | 12 | Grantham | 1:59.26 |
| 6 | 12 | Louis THOMPSON | 10 | Grantham | 1:54.91 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 13 | Matilda MCDONNELL | 12 | Grantham | 1:52.28 |
| 2 | 14 | Evangeline KINNEAR | 12 | Grantham | 1:51.41 |
| 3 | 15 | Esmé EVANS | 11 | Grantham | 1:50.00 |
| 4 | 16 | Emily CLAYTON | 11 | Grantham | 1:49.46 |
| 5 | 17 | Thomas KINNEAR | 14 | Grantham | 1:48.14 |
| 6 | 18 | Annabel HILLSON | 10 | Grantham | 1:45.25 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Gracie PAYNE | 12 | Grantham | 1:45.00 |
| 2 | 20 | Benjamin SHEARN | 11 | Grantham | 1:43.21 |
| 3 | 21 | Abigail TAYLOR | 11 | Grantham | 1:42.26 |
| 4 | 22 | Cyril BAO | 9 | Grantham | 1:41.17 |
| 5 | 23 | Emmeline GLEAVE | 10 | Grantham | 1:40.66 |
| 6 | 24 | Florence HARPER | 12 | Grantham | 1:39.67 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 25 | Thomas WHITTLE | 13 | Grantham | 1:38.92 |
| 2 | 26 | Caitlin IZOD | 12 | Grantham | 1:37.96 |
| 3 | 27 | Henry DOLAN | 12 | Grantham | 1:36.32 |
| 4 | 28 | William PENNOCK | 11 | Grantham | 1:36.12 |
| 5 | 29 | Olivia CHARITY | 13 | Grantham | 1:35.85 |
| 6 | 30 | Francesca WESTON | 10 | Grantham | 1:35.54 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 31 | Austin CHEN-REES | 12 | Grantham | 1:35.00 |
| 2 | 32 | Evelyn NICHOLLS | 12 | Grantham | 1:34.00 |
| 3 | 33 | Juliette KING | 13 | Grantham | 1:33.48 |
| 4 | 34 | Juliette KIM | 10 | Grantham | 1:33.11 |
| 5 | 35 | Elizabeth JONES | 15 | Grantham | 1:32.78 |
| 6 | 36 | Benjamin GODDARD | 12 | Grantham | 1:32.77 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 37 | Madeline SURTEES | 13 | Grantham | 1:32.67 |
| 2 | 38 | Hollie-Ann CROOK | 11 | Grantham | 1:31.98 |
| 3 | 39 | Isabelle CLAYTON | 13 | Grantham | 1:31.83 |
| 4 | 40 | Louis WRIGHT | 12 | Grantham | 1:30.44 |
| 5 | 41 | Octavia SHEARN | 13 | Grantham | 1:29.56 |
| 6 | 42 | Ella KHAMA | 11 | Grantham | 1:27.26 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 43 | Freddie HIRST | 11 | Grantham | 1:27.18 |
| 2 | 44 | Joshua KIM | 13 | Grantham | 1:27.06 |
| 3 | 45 | Mia PARAPIJONAVICIUTE | 16 | Grantham | 1:26.32 |
| 4 | 46 | Derrin BROCKLEBANK | 11 | Grantham | 1:25.66 |
| 5 | 47 | Leo BARNETT | 13 | Grantham | 1:25.48 |
| 6 | 48 | Ava-Grace GREGORY | 13 | Grantham | 1:25.00 |
| Heat Number - 9 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 49 | Jimmin BAO | 12 | Grantham | 1:24.92 |
| 2 | 50 | Elisabeth KINNEAR | 15 | Grantham | 1:24.37 |
| 3 | 51 | Grace HOWITT | 16 | Grantham | 1:21.56 |
| 4 | 52 | George LEONARD | 13 | Grantham | 1:20.36 |
| 5 | 53 | Elliot GLEAVE | 12 | Grantham | 1:19.47 |
| 6 | 54 | Sophie WARD | 16 | Grantham | 1:19.11 |
| Heat Number - 10 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 55 | Elena ALDENHOFF-KELLY | 17 | Grantham | 1:18.79 |
| 2 | 56 | Lucy ABBOTT | 13 | Grantham | 1:18.34 |
| 3 | 57 | Thomas HILLSON | 12 | Grantham | 1:17.50 |
| 4 | 58 | Lizzy LERESCHE HANDS | 14 | Grantham | 1:16.77 |
| 5 | 59 | Lexie SHEWAN | 15 | Grantham | 1:16.57 |
| 6 | 60 | Markas PARAPIJONAVICIU | 12 | Grantham | 1:16.08 |
| Heat Number - 11 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 61 | Amy TAYLOR | 14 | Grantham | 1:15.94 |
| 2 | 62 | Jessica - Rose DAVISON | 16 | Grantham | 1:12.05 |
| 3 | 63 | Ellena HOWITT | 14 | Grantham | 1:11.88 |
| 4 | 64 | Zach HOPKINSON | 16 | Grantham | 1:11.25 |
| 5 | 65 | Chloe HOPKINSON | 20 | Grantham | 1:10.08 |
| 6 | 66 | Isobel ALLSOP | 15 | Grantham | 1:09.56 |
| Heat Number - 12 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 68 | Annabelle JAY | 14 | Grantham | 1:06.98 |
| 2 | 70 | Jacob FISH | 16 | Grantham | 1:02.23 |
| 3 | 72 | Joshua CLARKE | 17 | Grantham | 57.98 |
| 4 | 71 | Ben CARLYLE | 15 | Grantham | 1:00.12 |
| 5 | 69 | Jack ZERAVICA | 17 | Grantham | 1:02.45 |
| 6 | 67 | Lucy WILLATTS | 14 | Grantham | 1:08.18 |