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. | 69,239,296 | 1.06 x 244 | 1 | 742 | |
| NTT Communications Corporation | 28,870,144 | 242 | 10 | 241 | |
| KDDI CORPORATION | 18,222,656 | 1.25 x 241 | 1 | 538 | |
| 4 | JCOM Co., Ltd. | 14,266,368 | 1.25 x 236 | 11 | 683 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 8,998,979 | 233 | 1 | 606 |
| 6 | ARTERIA Networks Corporation | 7,132,160 | 1.56 x 236 | 3 | 231 |
| 7 | Sony Network Communications Inc. | 4,341,248 | 1.22 x 237 | 1 | 346 |
| 8 | Internet Initiative Japan Inc. | 3,870,208 | 1.03 x 234 | 1 | 180 |
| 9 | BIGLOBE Inc. | 3,670,528 | 1.13 x 235 | 1 | 36 |
| 10 | OPTAGE Inc. | 3,070,976 | 232 | 2 | 81 |
| 11 | NTT DOCOMO, INC. | 2,563,584 | 1.19 x 233 | 1 | 1,179 |
| 12 | FUJITSU LIMITED | 2,493,184 | 232 | 1 | 47 |
| 13 | NTT PC Communications, Inc. | 2,331,392 | 1.56 x 233 | 1 | 171 |
| 14 | SoftBank Corp. | 2,045,184 | 233 | 4 | 200 |
| 15 | FreeBit Co.,Ltd. | 1,833,984 | 233 | 1 | 281 |
| 16 | NTT-ME Corporation | 1,759,488 | 242 | 1 | 52 |
| 17 | TOKAI Communications Corporation | 1,639,680 | 1.31 x 235 | 1 | 194 |
| 18 | IDC Frontier Inc. | 1,440,512 | 234 | 1 | 182 |
| 19 | Chubu Telecommunications Company, Inc. | 1,354,752 | 233 | 1 | 84 |
| 20 | Asahi Net | 1,277,952 | 1.13 x 235 | 1 | 64 |