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 | 14,630,656 | 1.32 x 237 | 1 | 8,720 | |
| TELEFONICA DE ESPANA S.A.U. | 10,599,936 | 1.04 x 241 | 2 | 240 | |
| VODAFONE ESPANA S.A.U. | 4,829,184 | 1.5 x 233 | 2 | 493 | |
| 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. | 985,344 | 1.31 x 235 | 2 | 371 |
| 7 | R Cable y Telecable Telecomunicaciones, S.A.U. | 856,064 | 1.38 x 227 | 2 | 63 |
| 8 | AIRE NETWORKS DEL MEDITERRANEO SL UNIPERSONAL | 740,096 | 1.41 x 237 | 4 | 489 |
| 9 | Euskaltel S.A. | 687,872 | 1.01 x 235 | 1 | 147 |
| 10 | LYNTIA NETWORKS S.A. | 404,992 | 1.19 x 237 | 5 | 243 |
| 11 | AVATEL TELECOM, SA | 379,904 | 1.25 x 236 | 8 | 511 |
| 12 | DIGI SPAIN TELECOM S.A | 354,816 | 235 | 1 | 14 |
| 13 | Consorci de Serveis Universitaris de Catalunya | 312,064 | 232 | 2 | 12 |
| 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. | 141,056 | 217 | 1 | 176 |
| 17 | Adamo Telecom Iberia S.A. | 138,496 | 1.63 x 235 | 1 | 117 |
| 18 | Servei Catala de la Salut | 131,072 | 0 | 1 | 3 |
| 19 | TELEFONICA GLOBAL SOLUTIONS SL | 103,424 | 1.5 x 233 | 2 | 34 |
| 20 | SAREnet, S.A. | 78,080 | 232 | 1 | 21 |