EVENT 306 Open/Male 12 /Under 50m Backstroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 2 | Gilbert NICHOLLS | 9 | Grantham | 1:15.00 |
| 3 | 3 | George PAYNE | 10 | Deepings | 1:15.00 |
| 4 | 5 | Ewan BELL | 10 | Lincoln Vulc | 1:06.50 |
| 5 | 6 | W POWELL-VREESWIJK | 10 | Grantham | 1:06.09 |
| 6 | 7 | Laurence DE ROSE | 9 | Deepings | 1:05.89 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 8 | Leo GOODWIN | 12 | Lincoln Vulc | 1:05.00 |
| 2 | 10 | George SPENCER | 9 | Grantham | 1:02.15 |
| 3 | 11 | Oscar BEMBRIDGE | 9 | Grantham | 59.89 |
| 4 | 12 | Ethan DANIELS | 11 | Lincoln Vulc | 58.49 |
| 5 | 13 | Henry BOWERS | 10 | Grantham | 58.00 |
| 6 | 14 | Jack DAWSON | 9 | Deepings | 57.77 |
| 7 | 17 | Jenson FRANCIS-SWABY | 10 | Co Lincoln P | 54.85 |
| 8 | 18 | Zachary SMITH GOMEZ | 10 | Lincoln Vulc | 54.30 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Edward BIRINY | 11 | Lincoln Vulc | 54.06 |
| 2 | 21 | Hector BARR | 10 | Deepings | 53.58 |
| 3 | 22 | Ethan COOK | 10 | Co Lincoln P | 53.21 |
| 4 | 24 | Charlie ARMSTRONG | 12 | Deepings | 51.15 |
| 5 | 26 | Finlay MATHESON | 9 | Co Lincoln P | 50.96 |
| 6 | 27 | Tom GRIFFIN | 11 | Deepings | 50.19 |
| 7 | 28 | Henry MOSS | 12 | Deepings | 50.14 |
| 8 | 29 | Finlay HODSON | 9 | Deepings | 49.91 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 30 | Albie WILSON | 9 | Deepings | 49.90 |
| 2 | 31 | Felix THORNDIKE | 9 | Lincoln Vulc | 49.52 |
| 3 | 32 | Henry LEONARD | 9 | Grantham | 47.36 |
| 4 | 33 | Jack PAIGE | 11 | Deepings | 47.21 |
| 5 | 34 | George DOLAN | 9 | Grantham | 47.18 |
| 6 | 35 | Ethan MEHTA | 11 | Lincoln Vulc | 47.10 |
| 7 | 36 | Benjamin BROWN | 10 | Deepings | 47.05 |
| 8 | 37 | Fox RICHARDSON | 9 | Co Lincoln P | 46.88 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 39 | Alex HUCKLE | 9 | Co Lincoln P | 46.58 |
| 2 | 40 | Leo FRANCZAK | 10 | Co Lincoln P | 46.11 |
| 3 | 41 | Lewis CLARKE | 12 | Co Lincoln P | 45.99 |
| 4 | 42 | Rory MACKFALL | 12 | Lincoln Vulc | 45.77 |
| 5 | 43 | Ralph MILNE | 10 | Grantham | 45.69 |
| 6 | 44 | Ethan PEART | 10 | Deepings | 45.42 |
| 7 | 45 | Siddharth SUTHAN | 11 | Co Lincoln P | 45.28 |
| 8 | 46 | Tom BARRATT | 11 | Gainsborough | 45.18 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 47 | Zhengxi (John) GUO | 9 | Grantham | 43.92 |
| 2 | 48 | Charles BLYTH | 11 | Lincoln Vulc | 43.51 |
| 3 | 49 | Jack ROWSELL | 11 | Co Lincoln P | 43.36 |
| 4 | 50 | Henry DOLAN | 12 | Grantham | 42.86 |
| 5 | 51 | Daniel GODDARD | 11 | Grantham | 42.70 |
| 6 | 55 | Zac RHOADES | 12 | Co Lincoln P | 41.23 |
| 7 | 56 | Liam EDMEADES | 10 | Deepings | 40.67 |
| 8 | 57 | Ksawery WRONSKI | 12 | Co Lincoln P | 40.10 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 59 | Louis WRIGHT | 12 | Grantham | 39.45 |
| 2 | 61 | Derrin BROCKLEBANK | 12 | Grantham | 37.96 |
| 3 | 63 | Zachary TOMLINSON | 12 | Co Lincoln P | 36.67 |
| 4 | 65 | Markas PARAPIJONAVICIU | 12 | Grantham | 33.63 |
| 5 | 64 | Toby EDMONDSON | 11 | Grantham | 36.60 |
| 6 | 62 | William PENNOCK | 12 | Grantham | 37.92 |
| 7 | 60 | Freddie HIRST | 11 | Grantham | 39.06 |
| 8 | 58 | George Arthur PYKE | 12 | Gainsborough | 39.96 |