EVENT 509 Men 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 1 | Austyn Manley | 13 | Nova Cent'n | 4:24.32 |
| 1 | 3 | Oliver Murray | 14 | Millfield | 4:28.41 |
| 2 | 5 | Jenson Owen | 14 | Co Sheffield | 4:30.26 |
| 3 | 7 | Dilanas Satavicius | 13 | Nuneaton | 4:24.51 |
| 4 | 9 | Lucas Bryant | 14 | Maidenhead | 4:21.63 |
| 5 | 8 | Matthew Lowther | 15 | Co South'ton | 4:26.33 |
| 6 | 6 | Reuben Thomas | 14 | Mt Kelly | 4:29.81 |
| 7 | 4 | Alexander Tew | 14 | York City | 4:26.25 |
| 8 | 2 | Reuben Hubinger | 14 | Repton | 4:32.24 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 11 | Oliver Handley | 15 | Croydon Amph | 4:27.64 |
| 1 | 13 | Charley King | 15 | Thanet Swim | 4:31.98 |
| 2 | 15 | Yassin Selmani | 15 | Barnet Copt | 4:21.85 |
| 3 | 17 | Makar Yakhno | 13 | Portsmouth N | 4:22.89 |
| 4 | 19 | Dylan Madican | 14 | Co Liverpool | 4:19.08 |
| 5 | 18 | Cillian Bramham | 15 | Camden Swiss | DN:C . |
| 6 | 16 | Jack Keers | 14 | Teddington | DN:C . |
| 7 | 14 | Layne Keyworth | 15 | Bassetlaw SS | 4:24.50 |
| 8 | 12 | Kian Lee | 15 | Co Peterboro | 4:26.62 |
| 9 | 10 | Thomas Marshall | 14 | Exeter City | 4:26.95 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 21 | Ethan Wills | 15 | Wycombe Dist | 4:23.42 |
| 1 | 23 | Jack Collins | 15 | Co Sheffield | 4:29.66 |
| 2 | 25 | Angus McKean | 16 | Wycombe Dist | 4:32.47 |
| 3 | 27 | Daniel Harris | 16 | Co Leicester | 4:23.01 |
| 4 | 29 | Barnaby Ryder | 16 | Mt Kelly | 4:23.16 |
| 5 | 28 | Sam Smith | 16 | Skipton | 4:21.61 |
| 6 | 26 | Anton Supov | 16 | Maidenhead | 4:23.48 |
| 7 | 24 | Finlay Richardson | 14 | Guildford Ct | DN:C . |
| 8 | 22 | Timothy Jones | 15 | Newquay | 4:27.75 |
| 9 | 20 | Edun Rowe | 15 | Northampton | 4:29.95 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 31 | Patch Robinson | 16 | teamipswich | 4:20.19 |
| 1 | 33 | Panos Angelakis | 16 | Mt Kelly | 4:26.44 |
| 2 | 35 | Max El-Mokadem | 15 | RTW Monson | 4:16.58 |
| 3 | 37 | Skye Sharples | 14 | Portsmouth N | 4:22.62 |
| 4 | 39 | Sami Benidir | 16 | Bo Newham | 4:34.00 |
| 5 | 38 | Jack Swindale | 15 | Co Peterboro | 4:25.67 |
| 6 | 36 | Harvey Reed | 16 | Co Birm'ham | 4:22.97 |
| 7 | 34 | Joshua Burkill | 14 | Sutton Cheam | 4:28.68 |
| 8 | 32 | Eamonn Djeridi | 15 | Royal Wolv | 4:24.24 |
| 9 | 30 | Monty Smith | 14 | Wycombe Dist | 4:20.25 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 41 | Kenechukwu Harris-Eze | 16 | Barnet Copt | 4:18.96 |
| 1 | 43 | Tain Phillips | 15 | Plymouth Lea | 4:29.19 |
| 2 | 45 | Andrew Clavis | 16 | Prescot | 4:21.18 |
| 3 | 47 | Max Harvey | 16 | Co Liverpool | 4:18.48 |
| 4 | 49 | Finn Ripley | 16 | Middlesboro | 4:21.21 |
| 5 | 48 | Daniel Moyses | 17 | Co Peterboro | 4:20.47 |
| 6 | 46 | Adam McCauley-Wright | 16 | Portsmouth N | 4:16.51 |
| 7 | 44 | George Turner | 16 | Newcastle | 4:17.62 |
| 8 | 42 | Damien Batchelor | 16 | Co Birm'ham | 4:16.77 |
| 9 | 40 | Benjamin Ross | 15 | Co Salford | 4:26.31 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 51 | Marcus Haigh | 15 | Wycombe Dist | 4:22.70 |
| 1 | 53 | Oliver Greaves | 16 | Wrekin SC | 4:20.35 |
| 2 | 55 | Daniel Walker | 16 | Nova Cent'n | 4:26.57 |
| 3 | 57 | Ben Uff | 15 | Mt Kelly | 4:30.46 |
| 4 | 59 | Adam Wright | 17 | Winsford | 4:14.82 |
| 5 | 58 | James Abulencia | 17 | Co Birm'ham | 4:17.12 |
| 6 | 56 | Daniel Payton | 14 | N & D PP SC | 4:22.27 |
| 7 | 54 | Todd Flynn | 17 | Epsom Dist | 4:18.50 |
| 8 | 52 | Luke Moore | 16 | Leatherhead | 4:17.34 |
| 9 | 50 | Lewis Turner | 17 | Winsford | 4:15.47 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 62 | George Moore | 17 | Co Leicester | 4:17.57 |
| 1 | 66 | Thomas Smith | 17 | RichmondDale | 4:14.63 |
| 2 | 70 | Samuel Cooke | 17 | Corby | 4:18.24 |
| 3 | 74 | Jack Rudd | 19 | Maidenhead | 4:11.52 |
| 4 | 78 | Ethan Rayment | 22 | Bath Univ | 4:08.47 |
| 5 | 76 | Ben Newell | 20 | Birm'ham Uni | 4:12.20 |
| 6 | 72 | Daniel Cox | 19 | Wycombe Dist | 4:09.21 |
| 7 | 68 | Reece Blackett | 17 | Newcastle | 4:10.83 |
| 8 | 64 | Billy Bainbridge | 17 | Teddington | 4:19.38 |
| 9 | 60 | Daniel Fielder | 17 | Gloucester | 4:21.18 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 63 | Daniel McGuinness | 17 | Basildon Ph | 4:18.70 |
| 1 | 67 | Danielius Tuma | 19 | Crawley | 4:10.80 |
| 2 | 71 | Samuel Tucker | 19 | Lboro Uni | 4:09.16 |
| 3 | 75 | B Howarth-Osborne | 19 | Co Sheffield | 4:13.78 |
| 4 | 79 | James Koch | 25 | Queensland | 3:53.14 |
| 5 | 77 | Jude Liddiard | 22 | Edinburgh Un | 4:09.19 |
| 6 | 73 | Jay Manners | 24 | N & D PP SC | 4:12.35 |
| 7 | 69 | Charlie Toms | 17 | Maxwell | 4:17.17 |
| 8 | 65 | Donatas Dragasius | 19 | Mt Kelly | 4:10.94 |
| 9 | 61 | George Pearson | 17 | Wycombe Dist | 4:09.74 |