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. | 70,163,968 | 1.06 x 244 | 1 | 784 | |
| NTT Communications Corporation | 29,038,080 | 242 | 9 | 294 | |
| KDDI CORPORATION | 18,496,576 | 1.25 x 241 | 1 | 557 | |
| 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 | 9,028,069 | 233 | 1 | 635 |
| 6 | ARTERIA Networks Corporation | 7,239,680 | 1.56 x 236 | 4 | 221 |
| 7 | Jupiter Telecommunications Co., Ltd. | 4,007,936 | 1.5 x 233 | 9 | 403 |
| 8 | Sony Network Communications Inc. | 3,890,176 | 1.22 x 237 | 1 | 118 |
| 9 | Internet Initiative Japan Inc. | 3,867,904 | 1.03 x 234 | 1 | 200 |
| 10 | BIGLOBE Inc. | 3,674,624 | 1.13 x 235 | 1 | 37 |
| 11 | OPTAGE Inc. | 3,175,168 | 233 | 2 | 98 |
| 12 | FUJITSU LIMITED | 3,070,720 | 232 | 1 | 52 |
| 13 | NTT DOCOMO, INC. | 2,771,968 | 233 | 1 | 1,079 |
| 14 | Ymobile Corporation | 2,738,688 | 0 | 1 | 40 |
| 15 | NTT PC Communications, Inc. | 2,349,056 | 1.56 x 233 | 1 | 173 |
| 16 | SoftBank Corp. | 2,050,240 | 232 | 2 | 183 |
| 17 | FreeBit Co.,Ltd. | 1,872,384 | 233 | 1 | 308 |
| 18 | NTT-ME Corporation | 1,759,488 | 242 | 1 | 52 |
| 19 | Amazon.com, Inc. | 1,659,648 | 1.13 x 232 | 1 | 264 |
| 20 | TOKAI Communications Corporation | 1,566,976 | 1.31 x 235 | 1 | 179 |