EVENT 303 Mixed 100m Backstroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Evie FELTON | 9 | Grantham | 2:20.00 |
| 3 | 2 | Lucia CORTON | 9 | Grantham | 2:10.00 |
| 4 | 3 | Evangeline KINNEAR | 11 | Grantham | 2:05.67 |
| 5 | 4 | Francesca WESTON | 9 | Grantham | 2:05.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Tilly WASKETT-BOOTH | 8 | Grantham | 2:04.00 |
| 2 | 6 | Emmeline GLEAVE | 9 | Grantham | 2:03.00 |
| 3 | 7 | Louis WRIGHT | 11 | Grantham | 2:00.00 |
| 4 | 8 | Emily CLAYTON | 10 | Grantham | 1:58.37 |
| 5 | 9 | Abigail TAYLOR | 10 | Grantham | 1:55.58 |
| 6 | 10 | Florence HARPER | 11 | Grantham | 1:55.10 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Matilda MCDONNELL | 11 | Grantham | 1:54.63 |
| 2 | 12 | Poppy BRODIE | 12 | Grantham | 1:50.28 |
| 3 | 13 | Daniel GODDARD | 9 | Grantham | 1:50.00 |
| 4 | 14 | Annabel HILLSON | 9 | Grantham | 1:45.00 |
| 5 | 15 | Madeline SURTEES | 12 | Grantham | 1:44.97 |
| 6 | 16 | Benjamin GODDARD | 11 | Grantham | 1:44.90 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 17 | Hollie-Anne CROOK | 10 | Grantham | 1:43.28 |
| 2 | 18 | Olivia CHARITY | 12 | Grantham | 1:41.86 |
| 3 | 19 | Honey FLOWER | 10 | Grantham | 1:40.00 |
| 4 | 20 | Henry DOLAN | 11 | Grantham | 1:39.25 |
| 5 | 21 | Freddie HIRST | 10 | Grantham | 1:38.64 |
| 6 | 22 | George LEONARD | 12 | Grantham | 1:36.13 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 23 | Juliette KIM | 9 | Grantham | 1:35.00 |
| 2 | 24 | Ella KHAMA | 10 | Grantham | 1:34.84 |
| 3 | 25 | Leo BARNETT | 12 | Grantham | 1:34.44 |
| 4 | 26 | Isabelle CLAYTON | 12 | Grantham | 1:34.17 |
| 5 | 27 | Derrin BROCKLEBANK | 10 | Grantham | 1:33.06 |
| 6 | 28 | Markas PARAPIJONAVICIU | 11 | Grantham | 1:31.88 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 29 | Octavia SHEARN | 12 | Grantham | 1:31.68 |
| 2 | 30 | Daisy CANTILLON | 12 | Grantham | 1:30.00 |
| 3 | 31 | Elliot GLEAVE | 11 | Grantham | 1:29.10 |
| 4 | 32 | Poppy HATHWAY | 13 | Grantham | 1:28.63 |
| 5 | 33 | Mia PARAPIJONAVICIUTE | 15 | Grantham | 1:27.86 |
| 6 | 34 | Lizzy LERESCHE HANDS | 13 | Grantham | 1:27.43 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 35 | Elisabeth KINNEAR | 14 | Grantham | 1:27.40 |
| 2 | 36 | Fabian KOLASA | 13 | Grantham | 1:27.15 |
| 3 | 37 | Thomas HILLSON | 11 | Grantham | 1:24.38 |
| 4 | 38 | Annie WEBSTER | 12 | Grantham | 1:24.27 |
| 5 | 39 | Amelia HATHWAY | 15 | Grantham | 1:22.46 |
| 6 | 40 | Lexie SHEWAN | 14 | Grantham | 1:21.41 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 41 | Alfie HAIGH | 15 | Grantham | 1:20.49 |
| 2 | 42 | Grace HOWITT | 15 | Grantham | 1:20.48 |
| 3 | 43 | Lucy ABBOTT | 12 | Grantham | 1:20.36 |
| 4 | 44 | Alexa WRIGHT | 16 | Grantham | 1:20.10 |
| 5 | 45 | Darcey WOOD | 13 | Grantham | 1:19.63 |
| 6 | 46 | Amy TAYLOR | 13 | Grantham | 1:19.22 |
| Heat Number - 9 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 47 | Elena ALDENHOFF-KELLY | 16 | Grantham | 1:19.11 |
| 2 | 48 | Ellena HOWITT | 13 | Grantham | 1:18.67 |
| 3 | 49 | Sophie WARD | 15 | Grantham | 1:16.78 |
| 4 | 50 | Annabelle JAY | 13 | Grantham | 1:16.07 |
| 5 | 51 | Lucy WILLATTS | 13 | Grantham | 1:14.20 |
| 6 | 52 | Megan BROWN | 15 | Grantham | 1:12.47 |
| Heat Number - 10 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 53 | Emilie WEBB | 14 | Grantham | 1:12.35 |
| 2 | 54 | Jessica - Rose DAVISON | 15 | Grantham | 1:12.05 |
| 3 | 55 | Zach HOPKINSON | 15 | Grantham | 1:10.92 |
| 4 | 56 | Ben CARLYLE | 14 | Grantham | 1:10.20 |
| 5 | 57 | Luke DAYBELL | 15 | Grantham | 1:10.09 |
| 6 | 58 | Grace TURNER | 17 | Grantham | 1:07.73 |
| Heat Number - 11 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 60 | Daniel DEGNAN | 16 | Grantham | 1:04.58 |
| 2 | 62 | Jacob FISH | 15 | Grantham | 1:02.71 |
| 3 | 64 | Joshua CLARKE | 16 | Grantham | 59.71 |
| 4 | 63 | Owen HATHWAY | 18 | Grantham | 1:02.01 |
| 5 | 61 | Jack ZERAVICA | 16 | Grantham | 1:03.66 |
| 6 | 59 | Benjamin ROBERTS | 15 | Grantham | 1:05.81 |