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 | 14,066,432 | 1.32 x 237 | 2 | 9,088 | |
| TELEFONICA DE ESPANA S.A.U. | 10,573,056 | 1.02 x 241 | 2 | 288 | |
| VODAFONE ESPANA S.A.U. | 5,388,800 | 1.5 x 233 | 2 | 775 | |
| 4 | VODAFONE ONO, S.A. | 2,850,816 | 238 | 2 | 93 |
| 5 | Entidad Publica Empresarial Red.es | 1,539,328 | 233 | 2 | 43 |
| 6 | XTRA TELECOM S.A. | 786,000 | 1.27 x 235 | 2 | 260 |
| 7 | R Cable y Telecable Telecomunicaciones, S.A.U. | 733,440 | 1.38 x 227 | 2 | 61 |
| 8 | Euskaltel S.A. | 677,888 | 1.01 x 235 | 1 | 128 |
| 9 | AIRE NETWORKS DEL MEDITERRANEO SL UNIPERSONAL | 643,840 | 1.84 x 237 | 3 | 473 |
| 10 | AVATEL TELECOM, SA | 363,520 | 1.38 x 235 | 36 | 1,024 |
| 11 | Consorci de Serveis Universitaris de Catalunya | 312,064 | 232 | 2 | 12 |
| 12 | Evolutio Business Connectivity S.L. | 225,280 | 232 | 4 | 121 |
| 13 | Servei Catala de la Salut | 196,608 | 0 | 1 | 7 |
| 14 | acens Technologies, S.L. | 177,408 | 232 | 1 | 107 |
| 15 | DIGI SPAIN TELECOM S.L.U. | 157,184 | 235 | 1 | 11 |
| 16 | Santander Global Technology, S.L.U | 145,408 | 0 | 1 | 130 |
| 17 | PROCONO S.A. | 138,752 | 0 | 1 | 163 |
| 18 | Adamo Telecom Iberia S.A. | 134,912 | 1.63 x 235 | 1 | 109 |
| 19 | TELEFONICA GLOBAL SOLUTIONS SL | 126,720 | 1.5 x 233 | 2 | 55 |
| 20 | SAREnet, S.A. | 77,824 | 232 | 1 | 20 |