EVENT 403 Mens MC 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 2 | Kian Saville | 16 | S10 | Daventry | 7:36.63 |
| 2 | 4 | Jacob Chambers | 13 | S8 | Co Manch Aq | 7:29.95 |
| 3 | 6 | Ted Smiley | 15 | S6 | Nova Cent'n | 7:14.23 |
| 4 | 8 | Owen Say | 15 | S9 | Bracknell | 6:45.44 |
| 5 | 7 | Christopher Pagan | 18 | S9 | Runnymede | 6:53.81 |
| 6 | 5 | Benjamin Pope | 12 | S8 | Havant & Wat | 7:21.03 |
| 7 | 3 | Matthew Buckland | 15 | S8 | London Dis | 7:35.01 |
| 8 | 1 | Alexander Hobbs | 11 | S7 | Mt Kelly | 8:54.34 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 10 | Samuel Whearty | 14 | S9 | Colchester | 6:27.10 |
| 2 | 12 | Samuel Baulch | 16 | S10 | Caerphilly | 6:19.50 |
| 3 | 14 | Alexander Taylor | 15 | S10 | Harrogate | 6:13.08 |
| 4 | 16 | Nathaniel Costigan | 16 | S12 | Satellite | 6:06.39 |
| 5 | 15 | Benjamin Brady | 18 | S10 | Croydon Amph | 6:10.99 |
| 6 | 13 | Steven McCormick | 15 | S9 | Fins | 6:17.42 |
| 7 | 11 | Nils Rehm | 15 | S9 | Bristol Nor | 6:26.47 |
| 8 | 9 | Leo McCrea | 13 | S6 | Bourmth Coll | 6:38.51 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 18 | Balthazar Bradshaw | 10 | S10 | Chelsea&West | 6:03.26 |
| 2 | 20 | Ethan Naisbitt | 13 | S9 | Pioneer 79 | 5:59.70 |
| 3 | 22 | Finlay Middleton | 14 | S8 | Mt Kelly | 5:55.95 |
| 4 | 24 | James Brown | 14 | S9 | Orion | 5:54.40 |
| 5 | 23 | Leo Johnson | 23 | S8 | Out To Swim | 5:54.71 |
| 6 | 21 | Luke Batty | 11 | S9 | Bolton Metro | 5:58.35 |
| 7 | 19 | Matthew Harding | 17 | S6 | Wirral Metro | 6:00.07 |
| 8 | 17 | Isaac Dunning | 19 | S9 | Inverclyde | 6:04.39 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 26 | Joshua Fruin | 14 | S10 | Portsmouth N | 5:44.64 |
| 2 | 28 | J Monaghan-Coombs | 18 | S9 | Saxon Crown | 5:32.72 |
| 3 | 30 | Connor Boyfield | 18 | S9 | Boston | 5:25.00 |
| 4 | 32 | Benjamin Grainger | 13 | S10 | Io Man | 5:19.99 |
| 5 | 31 | Scott Hadley | 18 | S8 | Orion | 5:24.65 |
| 6 | 29 | Reilly Shanahan | 16 | S9 | Shrewsbury | 5:26.95 |
| 7 | 27 | Dominic Redpath | 14 | S9 | Gosport | 5:38.32 |
| 8 | 25 | Adam Donnachie | 16 | S8 | Eastkilbride | 5:49.40 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 34 | Lewis Beagrie | 13 | S10 | Hamilton | 5:18.86 |
| 2 | 36 | Tom Piggott | 16 | S10 | Shrewsbury | 4:57.22 |
| 3 | 38 | Jacob Leach | 16 | S8 | Cockermouth | 4:51.74 |
| 4 | 40 | Craig McNeil | 19 | S10 | Man & NW Dis | 4:40.97 |
| 5 | 39 | Michael Jones | 22 | S7 | Mt Kelly | 4:45.78 |
| 6 | 37 | Joshua Grob | 20 | S8 | Middlesboro | 4:56.18 |
| 7 | 35 | Matthew Rishworth | 14 | S10 | Staines | 4:59.32 |
| 8 | 33 | Kieran Williams | 12 | S10 | Newquay | 5:19.95 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 42 | Jordan Catchpole | 17 | S14 | UEA Norwich | 4:29.33 |
| 2 | 44 | Benjamin Foulston | 16 | S10 | Nova Cent'n | 4:27.44 |
| 3 | 46 | Jonathan Booth | 18 | S9 | Bo Kirklees | 4:23.76 |
| 4 | 48 | Stephen Clegg | 21 | S12 | East Lothian | 4:14.26 |
| 5 | 47 | Kahoru Harazawa | 19 | S10 | Loughboro Un | 4:14.57 |
| 6 | 45 | Jonathan Eke | 20 | S10 | Co Cardiff | 4:24.14 |
| 7 | 43 | Jaxon Simmons | 16 | S13 | Co Peterboro | 4:29.24 |
| 8 | 41 | Oliver Carter | 16 | S10 | Carnegie | 4:36.78 |