List of the top 20 organizations with the largest IP allocations in Spain
| Rank | Name | IPv4 addresses | IPv6 /64 networks | AS numbers | Prefixes |
|---|---|---|---|---|---|
| Orange Espagne SA | 14,584,064 | 1.32 x 237 | 1 | 8,732 | |
| TELEFONICA DE ESPANA S.A.U. | 10,599,680 | 1.04 x 241 | 2 | 237 | |
| VODAFONE ESPANA S.A.U. | 4,870,400 | 1.5 x 233 | 2 | 649 | |
| 4 | VODAFONE ONO, S.A. | 1,988,608 | 238 | 1 | 69 |
| 5 | Entidad Publica Empresarial Red.es | 1,372,416 | 232 | 2 | 39 |
| 6 | XTRA TELECOM S.A. | 984,832 | 1.31 x 235 | 2 | 370 |
| 7 | R Cable y Telecable Telecomunicaciones, S.A.U. | 856,064 | 1.38 x 227 | 2 | 63 |
| 8 | Euskaltel S.A. | 687,616 | 1.01 x 235 | 1 | 146 |
| 9 | AIRE NETWORKS DEL MEDITERRANEO SL UNIPERSONAL | 669,184 | 1.03 x 237 | 4 | 472 |
| 10 | DIGI SPAIN TELECOM S.L.U. | 415,232 | 235 | 1 | 33 |
| 11 | AVATEL TELECOM, SA | 384,000 | 1.34 x 236 | 11 | 537 |
| 12 | Consorci de Serveis Universitaris de Catalunya | 312,064 | 232 | 2 | 12 |
| 13 | LYNTIA NETWORKS S.A. | 207,872 | 1.38 x 235 | 4 | 124 |
| 14 | acens Technologies, S.L. | 184,320 | 232 | 1 | 117 |
| 15 | Santander Global Technology, S.L.U | 145,664 | 0 | 1 | 132 |
| 16 | PROCONO S.A. | 140,800 | 217 | 1 | 175 |
| 17 | Adamo Telecom Iberia S.A. | 138,240 | 1.63 x 235 | 1 | 116 |
| 18 | Servei Catala de la Salut | 131,072 | 0 | 1 | 3 |
| 19 | TELEFONICA GLOBAL SOLUTIONS SL | 104,448 | 1.5 x 233 | 2 | 35 |
| 20 | SAREnet, S.A. | 78,080 | 232 | 1 | 21 |