| Name |
| RR10 League |
| Running Friends Devizes |
| Running Sisters Tayside |
| Running Sisters-Chiltern Region |
| Running Somewhere Else |
| Running Space |
| Running4CF |
| Runnyhoneys |
| RunThrough Events |
| Saints and Sinners Running Club |
| Sandhurst Joggers |
| Secret Run Club |
| Sedgemoor Striders |
| Shadwell Runners |
| Shawbury Joggers |
| Sheen Shufflers |
| Sheet Striders |
| Shepshed Running Club |
| Shepton Shufflers |
| Shinfield Running Club |
| Shore Footed |
| Shrewsbury Road Runners |
| Shrewton Running Club |
| Sidmouth Running Club |
| Skelmersdale Boundary Harriers |
| Sleaford Town Runners |
| SMACT |
| Smiley Paces |
| Somer Athletic Club |
| South Molton Strugglers |
| Sporting Club Inkberrow |
| St Austell Athletes Running Club |
| St Cyrus Solos |
| Staffordshire Moorlands Athletics Club |
| Star Running Club |
| Stevenage Phoenix Running Club |
| Stevenage Striders |
| Stopsley Striders |
| Stour Striders |
| Street Striders |
| Sunderland Strollers |
| Sutton Striders |
| Tadley Runners |
| Tadley Youth Running Club |
| Tadworth AC |
| Tankerton Running Group |
| Team Agile |
| Teign Valley Running Club |
| Teignbridge Trotters |
| The Holbeton Harriers |
| The Jim Miller 3 Miles Monthly Handicap |
| Thornbury Running Club |
| Three Counties Cross Country League |
| Tideswell Running Club |
| Torbay Running Club |
| Town and Country Harriers |
| Tracy Waites Soul Runners |
| Trail Outlaws Running Club |
| Tri-Hards |
| Truro Running Club |
| TT Runners |
| Up and Out Ladies Running Club |
| Vegan Running Club |
| Ware Joggers |
| Warleywoods Pacers (RIE) |
| Warriors Pentathlon & Athletic Club |
| Waterfront Community Runners |
| Wessex Road Runners |
| West End Runners |
| Weston Athletic Club |
| Weston Whippets |
| Wirksworth Running Club |
| Wooler Running Club |
| Worcestershire Trailblazers |
| Wormit Runners |
| Worthing Striders |
| Yaxley Runners & Joggers |
| Yeovil Town RRC |