EVENT 305 Men Open 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Lanre DADA | 12 | Maidstone SC | 6:08.78 |
| 2 | 2 | Eddie EVANS | 13 | Beckenham | 6:03.17 |
| 3 | 3 | Leo NIKOLIC | 13 | Dartford | 5:57.71 |
| 4 | 4 | William HOLDEN | 13 | Bexley | 5:47.46 |
| 5 | 5 | James TAYLOR-WRIGHT | 13 | RTW Monson | 5:43.27 |
| 6 | 6 | Stanley READER | 13 | Gwich Royals | 5:40.16 |
| 7 | 7 | Xian Ming LI | 14 | Tonbridge | 5:37.89 |
| 8 | 8 | Raef OWEN | 13 | Gwich Royals | 5:34.72 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 9 | Thomas BOYCE | 16 | Tonbridge | 5:23.84 |
| 2 | 10 | Charley KING | 14 | Thanet Swim | 5:22.89 |
| 3 | 11 | Marcus SWINERD | 16 | Dover Life | 5:22.53 |
| 4 | 12 | Finley GILHAM | 15 | Bexley | 5:19.30 |
| 5 | 13 | Alexander TOLLIT | 15 | RTW Monson | 5:19.22 |
| 6 | 14 | Sebastian WILLIAMS | 15 | Beckenham | 5:18.67 |
| 7 | 15 | Gregor HUTCHISON | 15 | Thanet Swim | 5:16.35 |
| 8 | 16 | Daniel OLIVER | 17 | Dartford | 5:16.18 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Teddy LEWIS | 16 | Saxon Crown | 5:13.31 |
| 2 | 20 | Ralph SEREKI | 14 | Maidstone SC | 5:08.30 |
| 3 | 22 | Harry COCKS | 14 | Thanet Swim | 5:06.81 |
| 4 | 24 | Sam MARTIN-YOUNG | 16 | Sevenoaks | 5:00.95 |
| 5 | 23 | Hayden ANNAN | 15 | RTW Monson | 5:06.37 |
| 6 | 21 | Kieran ELVY | 16 | Sevenoaks | 5:06.99 |
| 7 | 19 | Kevin CAO | 15 | Gwich Royals | 5:11.28 |
| 8 | 17 | James PAGE | 16 | Thanet Swim | 5:14.01 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 27 | Henry NORMAN | 15 | Bromley | 4:57.22 |
| 2 | 29 | Albert BRANCH | 17 | Sevenoaks | 4:56.90 |
| 3 | 31 | Bryan DINEV | 16 | Bexley | 4:54.66 |
| 4 | 34 | Max EL-MOKADEM | 14 | RTW Monson | 4:50.43 |
| 5 | 32 | Tom HAWKINS | 15 | Bexley | 4:53.82 |
| 6 | 30 | Matt BURROWS | 17 | Sevenoaks | 4:54.76 |
| 7 | 28 | Liam HAMP | 16 | Thanet Swim | 4:57.21 |
| 8 | 25 | James CLEAVER | 17 | Beckenham | 5:00.30 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 36 | Samuel LANDER | 16 | Bromley | 4:47.70 |
| 2 | 38 | Aran BISSETT | 14 | RTW Monson | 4:42.45 |
| 3 | 40 | Edward PAULING | 18 | Beckenham | 4:40.38 |
| 4 | 43 | Matthew ROGERS | 22 | Bromley | 4:28.90 |
| 5 | 42 | Oliver POPE | 17 | Thanet Swim | 4:30.09 |
| 6 | 39 | David ALLEN | 17 | Sevenoaks | 4:42.28 |
| 7 | 37 | Callum WOOLFENDEN | 17 | Beckenham | 4:42.98 |
| 8 | 35 | Harvey MAUNDERS | 18 | Gwich Royals | 4:49.00 |