EVENT 403 Boys 12 Yrs/Under 50m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 3 | 2 | Benjamin SHEARN | 14 | Grantham | 1:00.00 |
| 4 | 4 | Thomas KINNEAR | 10 | Grantham | 51.50 |
| 5 | 6 | William CASH | 13 | Deepings | 50.78 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 2 | 8 | Woody CLARK | 14 | Grantham | 49.82 |
| 3 | 9 | Derrin BROCKLEBANK | 14 | Grantham | 49.72 |
| 4 | 11 | Benjamin GODDARD | 13 | Grantham | 47.03 |
| 5 | 12 | Henry DOLAN | 13 | Grantham | 46.09 |
| 6 | 13 | George LEONARD | 12 | Grantham | 45.75 |
| 7 | 15 | George WOODHEAD | 13 | Retford | 43.98 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 19 | Oscar CHEN-REES | 12 | Grantham | 43.13 |
| 2 | 21 | Bobby WALLIS | 12 | Co Lincoln P | 41.28 |
| 3 | 22 | Logan MEGGETT | 10 | Co Lincoln P | 41.24 |
| 4 | 23 | Charlie ANDERSON | 11 | Retford | 41.20 |
| 5 | 24 | Bertie ROSE | 13 | Lincoln Vulc | 41.08 |
| 6 | 25 | Owen THOMAS | 11 | Retford | 40.59 |
| 7 | 26 | Michael BUNN | 11 | Lincoln Vulc | 40.51 |
| 8 | 28 | Tristan EKE | 11 | Co Lincoln P | 40.33 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 29 | Leo BARNETT | 12 | Grantham | 39.68 |
| 2 | 30 | Elliot GLEAVE | 13 | Grantham | 39.48 |
| 3 | 32 | Evan NIXON | 11 | Lincoln Vulc | 39.10 |
| 4 | 33 | Yu Ching (Eugene) CHEU | 11 | Grantham | 38.88 |
| 5 | 34 | Joshua KIM | 12 | Grantham | 38.64 |
| 6 | 35 | Oscar WOOD | 13 | Lincoln Vulc | 38.50 |
| 7 | 36 | Cole COOPER | 12 | Co Lincoln P | 38.13 |
| 8 | 37 | Zachary BARROWCLIFFE | 11 | Retford | 38.07 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 38 | Henry WILLERTON | 13 | Boston | 37.22 |
| 2 | 40 | Jonathan GBYLICZEK | 12 | Lincoln Vulc | 36.90 |
| 3 | 41 | Arlo HAMER | 12 | Co Lincoln P | 36.77 |
| 4 | 42 | Fabian KOLASA | 11 | Grantham | 36.66 |
| 5 | 43 | Matthew ROBERTS | 11 | Co Lincoln P | 36.59 |
| 6 | 44 | Dan PALMER | 13 | Co Lincoln P | 36.49 |
| 7 | 46 | Samuel NICHOLS | 12 | Grantham | 36.21 |
| 8 | 47 | Zachary WILSON | 12 | Lincoln Vulc | 35.89 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 48 | Luca HALLAM | 12 | Grantham | 35.80 |
| 2 | 49 | Corey HESELTINE | 12 | Retford | 35.70 |
| 3 | 51 | Stanley THURLOW | 12 | Lincoln Vulc | 35.00 |
| 4 | 52 | Finley ROWDING | 11 | Co Lincoln P | 34.94 |
| 5 | 53 | Joel SADLER | 11 | Grantham | 34.80 |
| 6 | 54 | Oliver CLARKE | 12 | Deepings | 34.74 |
| 7 | 56 | Oliver WILKINSON | 12 | Lincoln Vulc | 33.37 |
| 8 | 57 | Kieran BLOOR | 11 | Co Lincoln P | 33.30 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | YoB | Club | Time |
| 1 | 59 | Robbie DUFF | 11 | Lincoln Vulc | 32.26 |
| 2 | 62 | James CASH | 10 | Deepings | 31.41 |
| 3 | 64 | Reuben MEADOWS | 10 | Retford | 30.30 |
| 4 | 66 | Samuel GREEN | 10 | Retford | 27.50 |
| 5 | 65 | Riley HAMER | 10 | Co Lincoln P | 30.10 |
| 6 | 63 | Thomas COLLINS | 10 | Retford | 31.00 |
| 7 | 60 | Noah DEWSNAP | 11 | Retford | 31.51 |
| 8 | 58 | Connor SMITH | 10 | Grantham | 33.13 |