EVENT 104 Open/Male 12 /Under 50m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Cameron MILNE | 11 | Deepings | |
| 3 | 2 | Siddharth SUTHAN | 9 | Co Lincoln P | 1:30.00 |
| 4 | 3 | Theodor BULAT | 10 | Co Lincoln P | 1:10.21 |
| 5 | 4 | Daniel GODDARD | 9 | Grantham | 1:10.00 |
| 6 | 5 | Jenson MEIKLE | 12 | Lincoln Vulc | 1:10.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 6 | Sebastian MADDISON | 12 | Co Lincoln P | 1:10.00 |
| 2 | 7 | Zachary TOMLINSON | 10 | Co Lincoln P | 1:10.00 |
| 3 | 8 | Sam RHOADES | 12 | Co Lincoln P | 1:08.62 |
| 4 | 9 | Jude SMITH | 11 | Lincoln Vulc | 1:05.93 |
| 5 | 10 | William CASH | 11 | Deepings | 1:04.17 |
| 6 | 11 | Harry BEASTALL | 12 | Co Lincoln P | 1:01.95 |
| 7 | 13 | Inambao LUNGU | 10 | Lincoln Vulc | 1:01.92 |
| 8 | 14 | Arthur SAMMUT | 11 | Lincoln Vulc | 1:01.21 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 15 | Benjamin SHEARN | 10 | Grantham | 1:00.49 |
| 2 | 16 | Louis WRIGHT | 10 | Grantham | 1:00.00 |
| 3 | 17 | Woody CLARK | 10 | Grantham | 59.57 |
| 4 | 18 | Benjamin GODDARD | 11 | Grantham | 57.43 |
| 5 | 19 | Derrin BROCKLEBANK | 10 | Grantham | 56.47 |
| 6 | 20 | Harry MELDRUM | 12 | Co Lincoln P | 55.00 |
| 7 | 21 | Zaid OMRAN | 11 | Co Lincoln P | 55.00 |
| 8 | 22 | Thomas WHITTLE | 12 | Grantham | 55.00 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 23 | Finley JOINT | 11 | Grantham | 54.10 |
| 2 | 24 | Kai HILAROWICZ | 11 | Co Lincoln P | 53.94 |
| 3 | 25 | Jacob STAPLES | 12 | Lincoln Vulc | 52.21 |
| 4 | 26 | Bertie ROSE | 10 | Lincoln Vulc | 52.19 |
| 5 | 27 | James BACON | 10 | Grantham | 52.00 |
| 6 | 28 | Toby BROWN | 11 | Deepings | 51.78 |
| 7 | 29 | Freddie HIRST | 9 | Grantham | 50.18 |
| 8 | 30 | Finley WEST | 12 | Co Lincoln P | 49.73 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 31 | Oscar WOOD | 10 | Lincoln Vulc | 48.92 |
| 2 | 32 | Toby EDMONDSON | 9 | Grantham | 48.35 |
| 3 | 34 | Thomas KINNEAR | 12 | Grantham | 47.97 |
| 4 | 35 | M PARAPIJONAVICIUS | 10 | Grantham | 47.94 |
| 5 | 36 | Arlo HAMER | 11 | Co Lincoln P | 47.78 |
| 6 | 37 | Callum LOYNES | 12 | Co Lincoln P | 47.74 |
| 7 | 38 | Henry DOLAN | 10 | Grantham | 47.01 |
| 8 | 39 | Ryan BARGH | 11 | Co Lincoln P | 46.50 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 40 | Barnaby DURANT | 10 | Grantham | 45.90 |
| 2 | 41 | Leo BARNETT | 12 | Grantham | 45.47 |
| 3 | 42 | Bobby WALLIS | 11 | Co Lincoln P | 45.16 |
| 4 | 43 | Elliot GLEAVE | 11 | Grantham | 43.93 |
| 5 | 44 | George LEONARD | 11 | Grantham | 43.00 |
| 6 | 45 | Evan NIXON | 12 | Lincoln Vulc | 42.59 |
| 7 | 46 | Zachary WILSON | 12 | Lincoln Vulc | 42.12 |
| 8 | 48 | Joshua KIM | 11 | Grantham | 41.08 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 50 | Yu Ching CHEUNG | 12 | Grantham | 40.31 |
| 2 | 52 | Oliver CLARKE | 11 | Deepings | 38.68 |
| 3 | 54 | Oliver WILKINSON | 11 | Lincoln Vulc | 37.50 |
| 4 | 57 | Thomas HILLSON | 10 | Grantham | 36.70 |
| 5 | 55 | Cole COOPER | 12 | Co Lincoln P | 37.07 |
| 6 | 53 | Samuel NICHOLS | 12 | Grantham | 38.56 |
| 7 | 51 | Dan PALMER | 11 | Co Lincoln P | 40.20 |
| 8 | 49 | Henry WILLERTON | 10 | Boston | 40.54 |