EVENT 202 Boys Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 1 | Oleksandr MIALKOVSKYI | 12 | RTW Monson | 6:27.20 |
| 1 | 3 | Rohan BISSETT | 13 | RTW Monson | 5:57.70 |
| 2 | 5 | William WEST | 13 | Thanet Swim | 5:46.30 |
| 3 | 7 | Charlie COCKS | 13 | Thanet Swim | 5:42.50 |
| 4 | 9 | Harvey KERSHAW | 13 | Black Lion | 5:40.80 |
| 5 | 8 | Eddie EVANS | 14 | Beckenham | 5:41.95 |
| 6 | 6 | Charlie BRAID | 12 | White Oak | 5:46.20 |
| 7 | 4 | Damian DADKOV | 13 | Bromley | 5:54.60 |
| 8 | 2 | Wyn WILLIAMS | 13 | Bromley | 6:02.30 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 11 | Hayden SANDERS | 12 | Gwich Royals | 5:35.00 |
| 1 | 13 | Stanley READER | 14 | Gwich Royals | 5:29.70 |
| 2 | 17 | Alexander NIKOLIC | 17 | Dartford | 5:25.50 |
| 3 | 19 | Oscar BEHRENS | 17 | Maidstone SC | 5:18.70 |
| 4 | 21 | Liam STOCKWELL | 16 | Maidstone SC | 5:17.40 |
| 5 | 20 | Finn JACKSON | 15 | Maidstone SC | 5:17.60 |
| 6 | 18 | Joshua SCANLAN | 15 | Gwich Royals | 5:23.70 |
| 7 | 15 | Cameron THORNTON | 16 | Bexley | 5:28.00 |
| 8 | 12 | Xian Ming LI | 15 | Tonbridge | 5:32.30 |
| 9 | 10 | Lanre Thien DADA | 13 | Maidstone SC | 5:39.20 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 23 | Brian ZHANG | 16 | Ashford Sch | 5:14.91 |
| 1 | 25 | Finley GILHAM | 16 | Bromley | 5:08.40 |
| 2 | 28 | Timothy LEBERL | 21 | Beckenham | 4:54.42 |
| 3 | 30 | Callum WOOLFENDEN | 18 | Beckenham | 4:47.60 |
| 4 | 32 | Matthew ROGERS | 23 | Bromley | 4:32.60 |
| 5 | 31 | Tom HAWKINS | 16 | RTW Monson | 4:41.80 |
| 6 | 29 | Bryan DINEV | 17 | Bromley | 4:53.40 |
| 7 | 27 | Harry COCKS | 15 | Thanet Swim | 4:56.66 |
| 8 | 24 | Jeremiah CARNEGIE | 14 | Beckenham | 5:09.20 |
| 9 | 22 | Raef OWEN | 14 | Gwich Royals | 5:15.20 |