EVENT 501 Men 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 1 | Joseph Moment | 16 | KingstonHull | 4:06.81 |
| 1 | 3 | Ivan Hart | 16 | Millfield | 4:05.70 |
| 2 | 5 | Samuel Grimes | 16 | Wigan BEST | 4:05.42 |
| 3 | 7 | Samuel Lander | 16 | Mt Kelly | 4:04.31 |
| 4 | 9 | Llewellyn Porter | 14 | Camden Swiss | 4:03.45 |
| 5 | 8 | Jack Jenkinson | 16 | Skipton | 4:03.75 |
| 6 | 6 | Max Russell | 16 | Co Sheffield | 4:04.88 |
| 7 | 4 | Oscar Dodds | 16 | Co Leicester | 4:05.56 |
| 8 | 2 | Thomas Evans | 16 | Teddington | 4:06.66 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 11 | Jonathan Turck | 16 | Mt Kelly | 4:03.08 |
| 1 | 13 | Luke Clegg | 17 | Bo Kirklees | 4:02.96 |
| 2 | 15 | Moritz Baumgartner | 17 | Mt Kelly | 4:02.42 |
| 3 | 17 | Finn Broekhoven | 16 | Plymouth Lea | 4:02.08 |
| 4 | 19 | Alexander Harrand | 17 | Derventio | 4:01.57 |
| 5 | 18 | James Raw | 15 | Co Leicester | 4:01.78 |
| 6 | 16 | Nathan Potter | 17 | Maidenhead | 4:02.22 |
| 7 | 14 | Jack Booth Rudd | 18 | Maidenhead | 4:02.86 |
| 8 | 12 | Oliver Pope | 17 | Thanet Swim | 4:03.07 |
| 9 | 10 | George Pearson | 16 | Wycombe Dist | 4:03.45 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 21 | Mehdi El Mansar | 18 | Plymouth Lea | 4:01.17 |
| 1 | 23 | Daniel Cox | 18 | Wycombe Dist | 4:01.13 |
| 2 | 25 | Tom Hawkins | 15 | RTW Monson | 4:00.60 |
| 3 | 27 | Luca Staines | 18 | Swansea Uni | 3:59.41 |
| 4 | 29 | Matthew Baker | 16 | West Suffolk | 3:59.29 |
| 5 | 28 | Cameron Wrapson | 16 | Co Birm'ham | 3:59.38 |
| 6 | 26 | Finlay Chapman | 21 | Co Sheffield | 4:00.40 |
| 7 | 24 | Sam Williamson | 18 | Bath Univ | 4:00.81 |
| 8 | 22 | Ben Newell | 19 | Birm'ham Uni | 4:01.17 |
| 9 | 20 | Luke Jeal | 19 | Nova Cent'n | 4:01.48 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 32 | James McClure | 16 | Co Birm'ham | 3:58.99 |
| 1 | 36 | Michael Adeney | 19 | Co Manch Aq | 3:57.19 |
| 2 | 40 | Alexander Sargeant | 20 | Millfield | 3:55.70 |
| 3 | 44 | Reece Grady | 17 | Stockport Mo | 3:52.56 |
| 4 | 48 | William Ryley | 24 | Co Cardiff | 3:50.03 |
| 5 | 46 | Freddie Ashley-Sparks | 20 | Plymouth Lea | 3:51.53 |
| 6 | 42 | Nathan Hughes | 22 | Swansea Uni | 3:53.75 |
| 7 | 38 | Luke Booth | 17 | Rotherham Mo | 3:56.13 |
| 8 | 34 | Alexander Volkovoy | 17 | Co Salford | 3:58.41 |
| 9 | 30 | Isaac Dodds | 18 | Bath Univ | 3:59.26 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 33 | Ethan Rayment | 21 | Bath Univ | 3:58.95 |
| 1 | 37 | Christian Duetoft | 17 | Guildford Ct | 3:56.21 |
| 2 | 41 | Harry Wynne-Jones | 17 | Co Milton K | 3:54.87 |
| 3 | 45 | Collyn Gagne | 22 | SFA Canada | 3:52.49 |
| 4 | 49 | Tyler Melbourne-Smith | 17 | Co Liverpool | 3:48.93 |
| 5 | 47 | Thomas Trebilcock | 19 | Swansea Uni | 3:50.18 |
| 6 | 43 | Joseph Deighan | 19 | Swansea Uni | 3:53.41 |
| 7 | 39 | Luke McGee | 16 | Co Sund'land | 3:55.72 |
| 8 | 35 | Elijah Kendrick | 18 | Swansea Uni | 3:57.51 |
| 9 | 31 | David Annis | 16 | Royal Wolv | 3:59.04 |