List of the top 20 organizations with the largest IP allocations in Japan
| Rank | Name | IPv4 addresses | IPv6 /64 networks | AS numbers | Prefixes |
|---|---|---|---|---|---|
| SoftBank Corp. | 47,228,928 | 1.06 x 244 | 3 | 636 | |
| NTT Communications Corporation | 28,816,384 | 242 | 7 | 223 | |
| KDDI CORPORATION | 18,088,960 | 1.26 x 241 | 1 | 523 | |
| 4 | JCOM Co., Ltd. | 14,266,368 | 1.25 x 236 | 11 | 683 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 9,030,195 | 233 | 1 | 604 |
| 6 | ARTERIA Networks Corporation | 7,005,952 | 1.56 x 236 | 3 | 240 |
| 7 | Sony Network Communications Inc. | 3,851,264 | 1.03 x 237 | 1 | 75 |
| 8 | Internet Initiative Japan Inc. | 3,844,864 | 1.03 x 234 | 1 | 180 |
| 9 | BIGLOBE Inc. | 3,670,528 | 1.13 x 235 | 1 | 36 |
| 10 | OPTAGE Inc. | 3,067,392 | 232 | 2 | 68 |
| 11 | NTT DOCOMO, INC. | 2,669,056 | 1.3 x 233 | 1 | 1,237 |
| 12 | NTT PC Communications, Inc. | 2,621,952 | 1.56 x 233 | 1 | 461 |
| 13 | FreeBit Co.,Ltd. | 1,970,688 | 233 | 1 | 415 |
| 14 | FUJITSU LIMITED | 1,690,368 | 232 | 3 | 185 |
| 15 | TOKAI Communications Corporation | 1,640,192 | 1.31 x 235 | 1 | 195 |
| 16 | NTT-ME Corporation | 1,628,416 | 242 | 1 | 50 |
| 17 | IDC Frontier Inc. | 1,439,232 | 234 | 1 | 178 |
| 18 | Chubu Telecommunications Company, Inc. | 1,384,960 | 233 | 1 | 82 |
| 19 | Asahi Net | 1,277,952 | 1.13 x 235 | 1 | 64 |
| 20 | SAKURA Internet Inc. | 1,015,808 | 1.13 x 236 | 4 | 118 |