|
400 Metres (Standard: 51.00) |
| 45.95 | | Jamal Rhoden-Stevens | Shaftesbury Barnet Harriers | La Chaux-de-Fonds, SUI | 3 Jul | | |
| 47.08 | | Zak Curran | Windsor, Slough, Eton & Hounslow AC | Stratford (CT) | 17 Jul | | |
| 47.44 | | Chris McAlister | Thames Valley Harriers | Coulsdon | 30 Apr | | |
| 47.70 | | James Hanson (U23) | Woking AC | Watford | 20 Apr | | |
| 47.71 | | Jamal Clarke | Windsor, Slough, Eton & Hounslow AC | Berne, SUI | 14 Jun | | |
| 48.13 | | Thomas Staines | Basingstoke & Mid Hants AC | Pueblo CO, USA | 15 May | | |
| 48.14 | | Henry Fisher (U23) | Blackheath & Bromley Harriers AC | Birmingham Uni | 9 Jul | | |
| 48.58 | | Jacob Paul | Windsor, Slough, Eton & Hounslow AC | Stratford (CT) | 17 Jul | | |
| 48.68 | | Derek Kinlock (U23) | Croydon Harriers | Gillingham | 3 Sep | | |
| 48.96 | | Isaac Ogunlade | Herne Hill Harriers | Stratford (CT) | 14 Aug | | |
| 49.40 | | Nicholas Atwell (M35) | Thames Valley Harriers | Nuneaton | 8 Jun | | |
| 49.81 | | Klaysen Brandao Kafuti (U17) | Croydon Harriers | Kingston | 11 Jun | | |
| 49.89 | | Alex O'Callaghan-Brown (U23) | Blackheath & Bromley Harriers AC | Chelmsford | 18 Jun | | |
| 50.03 | | Edward Enser (U20) | Bracknell AC | Chelmsford | 12 Jun | | |
| 50.04 | | Ethan Curran (U17) | Crawley AC | Sports City | 8 Jul | | |
| 50.12 | | Craig Cox (M35) | Crawley AC | Stanford CA, USA | 19 Mar | | |
| 50.27 | 1 | Samuel Mowa (U17) | Blackheath & Bromley Harriers AC | Kingston | 15 May | | |
| 50.27 | | Philip Kastner (U23) | Thames Valley Harriers | Horspath | 23 Jul | | |
| 50.27 | | Max Perez-Diaz | Kingston AC & Polytechnic Harriers | Bedford | 21 Aug | | |
| 50.5 | | Adam Thompson | Herne Hill Harriers | Kingston | 7 May | | |
| 50.67 | | Luke Dronfield (U20) | Blackheath & Bromley Harriers AC | Eton | 10 Sep | | |
| 50.69 | | Richard Beak | Woking AC | Portsmouth | 3 Apr | | |
| 50.74 | | Hayden Christian (U17) | Guildford & Godalming AC | Bedford | 17 Sep | | |
| 50.94 | | Conor Kelly (U17) | Hercules Wimbledon AC | Carshalton | 12 Jun | | |
| 50.94 | | Joshua Martin (U17) | Hercules Wimbledon AC | Horspath | 16 Jul | | |
| 51.00 | | Keeran Sriskandarajah (U17) | Herne Hill Harriers | Horspath | 23 Jul | | |