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. | 70,164,992 | 1.06 x 244 | 1 | 785 | |
| NTT Communications Corporation | 29,039,104 | 242 | 9 | 296 | |
| KDDI CORPORATION | 18,499,648 | 1.25 x 241 | 1 | 561 | |
| 4 | Jupiter Telecommunication Co. Ltd | 10,332,160 | 233 | 1 | 260 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 9,162,469 | 233 | 1 | 639 |
| 6 | ARTERIA Networks Corporation | 7,245,056 | 1.56 x 236 | 4 | 264 |
| 7 | Jupiter Telecommunications Co., Ltd. | 4,007,936 | 234 | 9 | 404 |
| 8 | Internet Initiative Japan Inc. | 3,866,880 | 1.03 x 234 | 1 | 197 |
| 9 | So-net Entertainment Corporation | 3,863,552 | 1.22 x 237 | 1 | 115 |
| 10 | BIGLOBE Inc. | 3,674,624 | 1.13 x 235 | 1 | 37 |
| 11 | OPTAGE Inc. | 3,146,496 | 233 | 2 | 88 |
| 12 | FUJITSU LIMITED | 3,070,720 | 232 | 1 | 52 |
| 13 | NTT DOCOMO, INC. | 2,771,968 | 233 | 1 | 1,075 |
| 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 Mobile Corp. | 2,062,592 | 232 | 2 | 200 |
| 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 | 1,566,720 | 1.31 x 235 | 1 | 178 |