EVENT 20 Open/Male 50m Breaststroke - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Gilbert NICHOLLS | 9 | Grantham | 1:33.52 |
| 4 | 2 | Laurence DE ROSE | 9 | Deepings | 1:15.00 |
| 5 | 3 | Oscar BEMBRIDGE | 9 | Grantham | 1:12.75 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 4 | Henry BOWERS | 10 | Grantham | 1:03.78 |
| 3 | 5 | Jayden FOSTER | 9 | Louth | 1:03.00 |
| 4 | 6 | Tom GRIFFIN | 11 | Deepings | 1:01.99 |
| 5 | 7 | Arnas MESKAUSKAS | 9 | Louth | 1:01.76 |
| 6 | 8 | Adam AWAD | 9 | Boston | 59.99 |
| 7 | 9 | Jacob KING | 10 | Louth | 58.00 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Noah LAWRENCE | 10 | Louth | 57.60 |
| 2 | 11 | Zachary SMITH GOMEZ | 10 | Lincoln Vulc | 57.30 |
| 3 | 12 | Oliver ERSKINE | 13 | Lincoln TSA | 55.14 |
| 4 | 13 | George BRUMBY | 10 | Gainsborough | 55.00 |
| 5 | 14 | Henry SMITH | 12 | Skegness | 54.34 |
| 6 | 15 | Coen RUCK | 12 | Louth | 53.80 |
| 7 | 16 | Jack SMITH | 10 | Gainsborough | 53.55 |
| 8 | 17 | Henry LEONARD | 9 | Grantham | 52.11 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Oliver PYGOTT-HAMMOND | 10 | Grantham | 51.13 |
| 2 | 19 | Ethan PEART | 10 | Deepings | 50.73 |
| 3 | 20 | Cooper SPRING | 13 | Skegness | 50.64 |
| 4 | 21 | George DOLAN | 9 | Grantham | 50.05 |
| 5 | 22 | Harry BIBBY | 9 | Grantham | 50.00 |
| 6 | 23 | Felix THORNDIKE | 9 | Lincoln Vulc | 49.73 |
| 7 | 24 | Jack PAIGE | 11 | Deepings | 49.69 |
| 8 | 25 | Benjamin NOAKES | 12 | Louth | 49.15 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 26 | Oscar DOWNING | 14 | Lincoln TSA | 48.27 |
| 2 | 27 | Liam EDMEADES | 10 | Deepings | 48.11 |
| 3 | 28 | Damir IVANOVS | 11 | Boston | 46.12 |
| 4 | 29 | Jacob STAPLES | 14 | Lincoln Vulc | 46.07 |
| 5 | 30 | William PENNOCK | 12 | Grantham | 46.02 |
| 6 | 31 | Tom BARRATT | 11 | Gainsborough | 46.00 |
| 7 | 32 | Freddie HIRST | 11 | Grantham | 44.92 |
| 8 | 33 | Derrin BROCKLEBANK | 12 | Grantham | 44.05 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 34 | Bobby THAIN | 15 | Skegness | 43.23 |
| 2 | 35 | Benjamin SHEARN | 12 | Grantham | 43.23 |
| 3 | 36 | Bertie ROSE | 12 | Lincoln Vulc | 42.70 |
| 4 | 37 | Joshua HANKS | 16 | Louth | 42.54 |
| 5 | 38 | Elliot GLEAVE | 13 | Grantham | 42.42 |
| 6 | 39 | Louis WRIGHT | 12 | Grantham | 41.85 |
| 7 | 40 | Owen ZHANG | 14 | Gainsborough | 41.66 |
| 8 | 41 | Albert HAILE | 14 | Louth | 40.24 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 43 | Ollie BLANCHARD | 15 | Skegness | 38.80 |
| 2 | 45 | Henry DOLAN | 12 | Grantham | 38.27 |
| 3 | 47 | Ethan HUNTER | 15 | Lincoln Vulc | 34.30 |
| 4 | 49 | Ryan NORTON | 18 | Boston | 31.70 |
| 5 | 48 | Archie FRENCH | 16 | Lincoln Vulc | 33.64 |
| 6 | 46 | Elliot MCWHIRTER | 16 | Lincoln TSA | 36.41 |
| 7 | 44 | Samuel GRIFFIN | 13 | Deepings | 38.57 |
| 8 | 42 | Alfie BLADES | 15 | Gainsborough | 40.10 |