| Selos Informationssysteme GmbH | Lower Saxony |
| Seltec | Bavaria |
| Seltronics GmbH | Bavaria |
| SEM e.K. | North Rhine-Westphalia |
| SEMA GmbH | |
| semafora systems GmbH | |
| Semalytix GmbH | |
| Semantha | |
| Semantic Applications GmbH & Co. KG | |
| Sematell GmbH | Saarland |
| SEMCO Software Engineering GmbH | Bavaria |
| SEMICON Europa | Berlin |
| SEMIKRON Elektronik GmbH & Co. KG | Bavaria |
| Semil Green Web UG (haftungsbeschränkt) | |
| semio:bit UG (haftungsbeschränkt) | Berlin |
| SEMKNOX GmbH | |
| Sempai IT Consulting GmbH | |
| Semron GmbH | |
| Semtech GmbH | Bavaria |
| Semtrix GmbH | |
| Semvox GmbH | Saarland |
| Senior Computer Lab | Hesse |
| Sennheiser electronic GmbH & Co. KG | Lower Saxony |
| Senodis Technologies GmbH | |
| Senorics GmbH | |
| SeNostic GmbH | |
| SenoTec Ochmann GmbH | North Rhine-Westphalia |
| Sension GmbH | |
| SensoPart Industriesensorik GmbH | Baden-Württemberg |
| Sensorberg GmbH | |
| Senstar GmbH | Baden-Württemberg |
| SENTECH Instruments GmbH | |
| Sentronic GmbH | Saxony |
| Sentronics Metrology GmbH | |
| Seo Agentur Ara8 GmbH | Bavaria |
| SEO Agentur Digitaleffects GmbH | |
| SEO Agentur Rosenheim | |
| SEO Bavaria GmbH | |
| SEO Dienst | |
| SEO Doktor | |
| SEO GmbH | Berlin |
| SEO und SEA | Saxony |
| SEO-Ambulance+de | |
| SEO-Analyse.com | Baden-Württemberg |
| SEO-HD Suchmaschinenoptimierung | |
| SEO-Küche Internet Marketing GmbH & Co. KG | Bavaria |
| SEO.Organic | Hamburg |
| Seobility GmbH | Bavaria |
| Seobunny | North Rhine-Westphalia |
| Seocomplete GmbH | North Rhine-Westphalia |