| Atom Studios | Madrid |
| aTon Systems | Barcelona |
| ATP Software | Barcelona |
| Atribus-Gespi 2015, S.L. | Valencia |
| Attender | Barcelona |
| Audea | Madrid |
| Audinfor System, S.L. | Zaragoza |
| Audits Consulting Management, S.L. | |
| Augmented Reality Software, S.L. | Salamanca |
| Aulambra | Madrid |
| Aulatina Consulting, S.L. | Málaga |
| Aumenta Solutions | Barcelona |
| Aunoa | Valencia |
| Ausatel | Barcelona |
| Auta Comunicaciones, S.L. | Valencia |
| AuthUSB, S.L. | Pontevedra |
| Autodrive Solutions | Madrid |
| Automated Devices | Madrid |
| Automàtica Electrònica i Control, S.L. | Barcelona |
| Avalon Informática y Servicios, S.L. | Madrid |
| Avalon Programming Solutions, S.L. | Salamanca |
| Avalora Tecnologías de la Información, S.A. | Madrid |
| Avandtel | Sevilla |
| Avansis Integración, S.L. | Madrid |
| AvanSoft | Madrid |
| Avantgeo, S.L. | Valencia |
| Avantia Ingenieria de Vanguardia, S.L. | Alicante |
| Avantigrup, S.C.P. | Barcelona |
| Avantio | Valencia |
| Avanza Consulting, S.L. | Salamanca |
| Avanze Nuevas Tecnologias | Madrid |
| Avanzo | Madrid |
| Avatar Cognition | Barcelona |
| Avellana Digital, S.L. | Tarragona |
| Aver Technology | Barcelona |
| Avocaty | Madrid |
| Avryde2000, S.L. | Valencia |
| Awara IT | Barcelona |
| Aware Health Communication, S.L. | Barcelona |
| AWSensors | Valencia |
| Axarnet Comunicaciones, S.L. | Valencia |
| Axedra | Santa Cruz de Tenerife |
| Axión Infraestructura de Telecomunicaciones, S.A.U. | Sevilla |
| Axon Arquitectura Digital | Tarragona |
| Axos Soluciones Visuales, S.L. | Madrid |
| AXPE Consulting, S.L. | Madrid |
| Ayanet RRHH | Zaragoza |
| Aydai | Valencia |
| Ayesa | Sevilla |
| AyZWeb | Valencia |