| Company name | Company type(s) | Gold Standard Status |
| Activision Blizzard Media | Direct Sellers (owned inventory) | Registered |
| AdColony | Sell Side Support (non-owned inventory) | 2.0 |
| Adform | Sell Side Support (non-owned inventory) Buy Side Support (Tech platform services) |
1.1 |
| AdInMo | Buy Side Support (Tech platform services) | Registered |
| adverty | Sell Side Support (non-owned inventory) | 1.0 |
| Admix | Sell Side Support (non-owned inventory) | Registered |
| agenda21 | Buyer Planner | 1.1 |
| AutoTrader | Direct Sellers (owned inventory) | 2.0 |
| Amazon Advertising | Buy Side Support (Tech platform services) Buyer Planner |
2.0 |
| Amboee | Buy Side Support (Tech platform services) | Registered |
| Anzu Virtual Reality | Full Service Support | 2.0 |
| Audience Store | Buyer Activation | 2.0 |
| Authorised Buyers, Google | Buy Side Support (Tech platform services) | 2.0 |
| Awin | Buyer Activation | Registered |
| Bauer Media | Direct Sellers (owned inventory) | 2.0 |
| Bidstack | Sell Side Support (non-owned inventory) Buy Side Support (Tech platform services) |
1.1 |
| Blis | Buy Side Support (Tech platform services) | 1.1 |
| Captify | Buyer Activation | 1.1 |
| CAVAI | Buy Side Support (Tech platform services) | Registered |
| Collective | Direct Sellers (owned inventory) Sell Side Support (non-owned inventory) |
1.1 |
| Crimtan | Buy Side Support (Tech platform services) | 1.1 |
| DAZN | Direct Sellers (owned inventory) | 1.1 |
| Discovery Networks | Direct Sellers (owned inventory) | Registered |
| eBay | Direct Sellers (owned inventory) | 2.0 |
| encore | Buyer Activation Buyer Planner |
2.0 |
| ESI Media | Direct Sellers (owned inventory) | 1.0 |
| Essence | Buyer Planner | 2.0 |
| Direct Sellers (owned inventory) | 2.0 | |
| Fifty | Buy Side Support (Tech platform services) | Registered |
| FreeWheel | Sell Side Support (non-owned inventory) | 2.0 |
| Global | Direct Sellers (owned inventory) | 2.0 |
| Goodstuff Holdings Ltd | Buyer Planner | Registered |
| GroupM UK | Buyer Planner | 2.0 |
| GumGum | Sell Side Support (non-owned inventory) | 2.0 |
| Havas | Buyer Activation | 1.1 |
| Haymarket | Direct Sellers (owned inventory) | 1.1 |
| Hearst | Direct Sellers (owned inventory) | 2.0 |
| Hello! | Direct Sellers (owned inventory) | 2.0 |
| Immediate Media | Direct Sellers (owned inventory) | 1.1 |
| Index Exchange | Sell Side Support (non-owned inventory) | 2.0 |
| Inskin | Sell Side Support (non-owned inventory) | 2.0 |
| Direct Sellers (owned inventory) | 2.0 | |
| IPGMediabrands | Buyer Planner | 2.0 |
| JustPremium | Sell Side Support (non-owned inventory) | 2.0 |
| LADbible group | Direct Sellers (owned inventory) | 2.0 |
| LiveScore | Direct Sellers (owned inventory) | 2.0 |
| Loopme | Buy Side Support (Tech platform services) | 1.1 |
| MatterKind | Buyer Activation | 2.0 |
| m/Six | Buyer Planner | 2.0 |
| Magnite | Sell Side Support (non-owned inventory) | 2.0 |
| MailMetroMedia | Direct Sellers (owned inventory) | 2.0 |
| Mediacom | Buyer Planner | 2.0 |
| Mindshare | Buyer Planner | 2.0 |
| MIQ | Buyer Activation | 1.1 |
| Mobsta | Buyer Activation | 2.0 |
| Navigate Digital | Buyer Planner | 2.0 |
| Nativo | Sell Side Support (non-owned inventory) | 2.0 |
| News UK | Direct Sellers (owned inventory) | 2.0 |
| OCM Digital Media | Sell Side Support (non-owned inventory) | Registered |
| OMG | Buyer Activation Buyer Planner |
2.0 |
| OpenX | Buy Side Support (Tech platform services) | 2.0 |
| Direct Sellers (owned inventory) | Registered | |
| Playground XYZ | Sell Side Support (non-owned inventory) | Registered |
| Publicis Media | Buyer Activation Buyer Planner |
2.0 |
| Pubmatic | Buy Side Support (Tech platform services) | 2.0 |
| Quantcast | Buyer Activation | 2.0 |
| Reach Solutions | Direct Sellers (owned inventory) | 2.0 |
| Rezonence | Sell Side Support (non-owned inventory) | 1.1 |
| Samsung Ads | Direct Sellers (owned inventory) | 1.0 |
| Seedtag | Sell Side Support (non-owned inventory) | Registered |
| Shpock | Direct Sellers (owned inventory) | 1.1 |
| Sky | Direct Sellers (owned inventory) | 2.0 |
| Smadex | Sell Side Support (non-owned inventory) Buy Side Support (Tech platform services) |
1.1 |
| Snap Inc. | Direct Sellers (owned inventory) | Registered |
| Sovrn | Sell Side Support (non-owned inventory) | 1.1 |
| Spiritmedia | Buyer Planner | 1.1 |
| Spotify | Direct Sellers (owned inventory) | 1.1 |
| SpotX | Sell Side Support (non-owned inventory) | 2.0 |
| Syzygy | Buy Side Support (Tech platform services) Buyer Planner |
1.1 |
| Taboola | Full Service Support | Registered |
| TAN Media | Full Service Support | 2.0 |
| Teads | Sell Side Support (non-owned inventory) | 2.0 |
| The Guardian | Direct Sellers (owned inventory) | 1.1 |
| The Kite Factory | Buyer Planner | 1.1 |
| The Mediagrid | Sell Side Support (non-owned inventory) | 1.1 |
| The Telegraph | Direct Sellers (owned inventory) | 2.0 |
| the7Stars | Buyer Activation Buyer Planner |
2.0 |
| TheTradeDesk | Buy Side Support (Tech platform services) | 2.0 |
| TikTok | Direct Sellers (owned inventory) | 2.0 |
| tnbc Live | Direct Sellers (owned inventory) | Registered |
| Total Media | Buyer Planner | 1.1 |
| TripAdvisor | Direct Sellers (owned inventory) | 1.1 |
| triplelift | Sell Side Support (non-owned inventory) | 1.1 |
| Twitch | Direct Sellers (owned inventory) | Registered |
| Direct Sellers (owned inventory) | 1.1 | |
| Unruly | Full Service Support | 2.0 |
| vdx.tv | Full Service Support | 2.0 |
| venatus | Sell Side Support (non-owned inventory) | 2.0 |
| Verizon Media | Direct Sellers (owned inventory) Sell Side Support (non-owned inventory) Buy Side Support (Tech platform services) |
1.1 |
| Vevo | Direct Sellers (owned inventory) | 1.1 |
| Vibrant | Sell Side Support (non-owned inventory) | Registered |
| Video Intelligence | Direct Sellers (owned inventory) | Registered |
| Wavemaker | Buyer Planner | 2.0 |
| Xandr | Sell Side Support (non-owned inventory) Buy Side Support (Tech platform services) |
2.0 |
| Xaxis UK | Buyer Activation | 2.0 |
| YouTube, Google | Direct Sellers (owned inventory) | 2.0 |