EVENT 39 Open/Male 50m Backstroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Gilbert NICHOLLS | 9 | Grantham | 1:20.00 |
| 3 | 3 | Henry SMITH | 12 | Skegness | 1:00.25 |
| 4 | 4 | Alex BARTLE | 10 | Boston | 1:00.24 |
| 5 | 5 | Oscar BEMBRIDGE | 9 | Grantham | 59.89 |
| 6 | 6 | James NICASSIO | 11 | Louth | 59.27 |
| 7 | 7 | Oliver PYGOTT-HAMMOND | 10 | Grantham | 56.71 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 8 | Ted LIBELL | 10 | Louth | 56.00 |
| 2 | 9 | Zachary SMITH GOMEZ | 10 | Lincoln Vulc | 54.30 |
| 3 | 10 | Edward BIRINY | 11 | Lincoln Vulc | 54.06 |
| 4 | 11 | George CASSWELL | 9 | Gainsborough | 54.00 |
| 5 | 12 | Breden O'BRIEN | 9 | Skegness | 51.80 |
| 6 | 13 | Harry BIBBY | 9 | Grantham | 50.47 |
| 7 | 14 | Coen RUCK | 12 | Louth | 47.78 |
| 8 | 15 | Tommy-Lucas PARKINSON | 11 | Gainsborough | 47.38 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 16 | Henry LEONARD | 9 | Grantham | 47.36 |
| 2 | 17 | George DOLAN | 9 | Grantham | 47.18 |
| 3 | 18 | Noah LAWRENCE | 10 | Louth | 45.83 |
| 4 | 19 | Ethan PEART | 10 | Deepings | 45.42 |
| 5 | 20 | Finley MARSH-DEAN | 11 | Louth | 45.15 |
| 6 | 21 | Theodore DONALDSON | 12 | Gainsborough | 45.00 |
| 7 | 22 | Cooper SPRING | 13 | Skegness | 44.25 |
| 8 | 23 | Benjamin SHEARN | 12 | Grantham | 44.13 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 24 | Damir IVANOVS | 11 | Boston | 43.37 |
| 2 | 25 | Teddy LAWLOR | 11 | Louth | 43.15 |
| 3 | 26 | Henry DOLAN | 12 | Grantham | 42.86 |
| 4 | 27 | Daniel GODDARD | 11 | Grantham | 42.70 |
| 5 | 28 | George WHITE | 12 | Louth | 42.27 |
| 6 | 29 | Henry EVANS | 12 | Louth | 40.20 |
| 7 | 30 | Hugo BRAILSFORD | 12 | Deepings | 39.46 |
| 8 | 31 | Benjamin GODDARD | 13 | Grantham | 39.27 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 32 | Evan WILSON | 12 | Gainsborough | 39.24 |
| 2 | 33 | Freddie HIRST | 11 | Grantham | 39.06 |
| 3 | 34 | George WOODHEAD | 12 | Gainsborough | 39.00 |
| 4 | 35 | William PENNOCK | 12 | Grantham | 37.92 |
| 5 | 36 | Cameron JAMISON | 11 | Lincoln TSA | 37.81 |
| 6 | 37 | Jacob STAPLES | 14 | Lincoln Vulc | 37.23 |
| 7 | 38 | Zachary LAWRENCE | 13 | Louth | 37.19 |
| 8 | 39 | Reid HATCH | 13 | Gainsborough | 37.00 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 41 | Oscar HE | 13 | Gainsborough | 36.61 |
| 2 | 43 | Cameron MILNE | 13 | Deepings | 35.39 |
| 3 | 45 | Owen ZHANG | 14 | Gainsborough | 32.66 |
| 4 | 47 | Layton ANNISON-SNOWDEN | 16 | Louth | 28.27 |
| 5 | 46 | Ryan NORTON | 18 | Boston | 30.12 |
| 6 | 44 | George LEONARD | 13 | Grantham | 35.15 |
| 7 | 42 | Thomas HILLSON | 12 | Grantham | 35.89 |
| 8 | 40 | Albert HAILE | 14 | Louth | 36.93 |