EVENT 624 Open/Male 12/13 Yrs 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 2 | Jonathan Khirul | 12 | Bo Newham | 6:55.17 |
| 2 | 4 | Tyatt Cole | 12 | Bo Southend | 6:47.97 |
| 3 | 6 | Kevin Susman | 12 | Bo Waltham F | 6:38.40 |
| 4 | 8 | Kaloyan Manolchev | 12 | Basildon Ph | 6:31.83 |
| 5 | 7 | Kian Parsons | 12 | Thurrock | 6:37.23 |
| 6 | 5 | Yavor Velev | 12 | Thurrock | 6:47.33 |
| 7 | 3 | Nathan Alumanah | 12 | Thurrock | 6:48.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 10 | David Caseriu | 13 | Thurrock | 6:28.89 |
| 1 | 13 | Atticus Frost | 13 | DunmowAtlant | 6:24.71 |
| 2 | 15 | Patrick Iancu | 12 | Bo Southend | 6:17.81 |
| 3 | 17 | Evan Cotter | 13 | Thurrock | 6:12.21 |
| 4 | 19 | Lucas Vong | 12 | Bo Newham | 6:08.70 |
| 5 | 18 | Alexandru Burciu | 13 | Bo Newham | 6:12.13 |
| 6 | 16 | S Higgon-Williams | 13 | Harwich DP | 6:16.70 |
| 7 | 14 | Tyler Dean | 13 | Harwich DP | 6:19.53 |
| 8 | 12 | Stanley Taylor | 13 | Colchester | 6:25.26 |
| 9 | 9 | Samuel Fallahnia | 13 | Epping For't | 6:29.71 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 21 | Apollo Pop | 13 | Chelmsford | 6:04.81 |
| 1 | 24 | Alexander Nixon | 13 | Killerwhales | 5:59.68 |
| 2 | 26 | Matthew Jarratt | 13 | DunmowAtlant | 5:57.09 |
| 3 | 28 | George Headford | 12 | Basildon Ph | 5:54.00 |
| 4 | 30 | Senan Brullo | 13 | New Hall | 5:51.58 |
| 5 | 29 | Nicholas Rasnita | 13 | Bo Newham | 5:53.00 |
| 6 | 27 | Archie Georgakis | 13 | Basildon Ph | 5:55.94 |
| 7 | 25 | Marcus Tsoi | 13 | Bo Newham | 5:59.27 |
| 8 | 23 | Kaleb McClimont | 12 | Killerwhales | 6:03.17 |
| 9 | 20 | Victor Dryankov | 12 | Thurrock | 6:08.53 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 33 | Jude Baldock | 12 | Bo Waltham F | 5:49.48 |
| 1 | 35 | David Hoara | 12 | Thurrock | 5:47.81 |
| 2 | 37 | Fletcher Waugh | 12 | Colchester | 5:43.30 |
| 3 | 39 | Shane Grant | 13 | Killerwhales | 5:34.46 |
| 4 | 41 | Dylan Lam | 13 | Bo Newham | 5:28.48 |
| 5 | 40 | Jack Lees | 13 | Epping For't | 5:30.70 |
| 6 | 38 | William Ford | 13 | Killerwhales | 5:41.20 |
| 7 | 36 | Tobias Watson | 13 | Bo Southend | 5:47.30 |
| 8 | 34 | George Connor | 13 | Colchester | 5:48.38 |
| 9 | 31 | Joseph Payne | 12 | Colchester | 5:49.74 |