List of the top 20 organizations with the largest IP allocations in Japan
| Rank | Name | IPv4 addresses | IPv6 /64 networks | AS numbers | Prefixes |
|---|---|---|---|---|---|
| Softbank BB Corp. | 71,062,528 | 1.06 x 244 | 1 | 782 | |
| NTT Communications Corporation | 29,095,424 | 242 | 9 | 282 | |
| KDDI CORPORATION | 18,427,968 | 1.25 x 241 | 1 | 544 | |
| 4 | Jupiter Telecommunication Co. Ltd | 10,332,160 | 1.06 x 236 | 1 | 289 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 8,995,654 | 233 | 1 | 637 |
| 6 | ARTERIA Networks Corporation | 7,236,352 | 1.56 x 236 | 4 | 217 |
| 7 | Sony Network Communications Inc. | 4,091,904 | 1.22 x 237 | 1 | 143 |
| 8 | Jupiter Telecommunications Co., Ltd. | 4,007,936 | 1.5 x 233 | 9 | 403 |
| 9 | Internet Initiative Japan Inc. | 3,863,296 | 1.03 x 234 | 1 | 191 |
| 10 | BIGLOBE Inc. | 3,670,528 | 1.13 x 235 | 1 | 36 |
| 11 | OPTAGE Inc. | 3,173,632 | 233 | 2 | 92 |
| 12 | FUJITSU LIMITED | 3,000,832 | 232 | 1 | 52 |
| 13 | NTT DOCOMO, INC. | 2,820,864 | 1.03 x 233 | 1 | 1,134 |
| 14 | NTT PC Communications, Inc. | 2,345,984 | 1.56 x 233 | 1 | 173 |
| 15 | SoftBank Corp. | 2,044,416 | 232 | 2 | 173 |
| 16 | FreeBit Co.,Ltd. | 1,884,416 | 233 | 1 | 304 |
| 17 | NTT-ME Corporation | 1,759,488 | 242 | 1 | 52 |
| 18 | TOKAI Communications Corporation | 1,635,584 | 1.31 x 235 | 1 | 181 |
| 19 | IDC Frontier Inc. | 1,452,800 | 234 | 2 | 204 |
| 20 | Chubu Telecommunications Company, Inc. | 1,229,824 | 233 | 1 | 75 |