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. | 47,217,152 | 1.06 x 244 | 3 | 611 | |
| NTT Communications Corporation | 28,783,872 | 242 | 7 | 220 | |
| KDDI CORPORATION | 18,088,192 | 1.26 x 241 | 1 | 522 | |
| 4 | JCOM Co., Ltd. | 14,266,368 | 1.25 x 236 | 11 | 683 |
| 5 | Research Organization of Information and Systems, National Institute of Informa | 9,024,547 | 233 | 1 | 612 |
| 6 | ARTERIA Networks Corporation | 7,006,976 | 1.56 x 236 | 3 | 250 |
| 7 | Internet Initiative Japan Inc. | 3,910,400 | 1.03 x 234 | 1 | 181 |
| 8 | Sony Network Communications Inc. | 3,867,648 | 1.03 x 237 | 1 | 76 |
| 9 | BIGLOBE Inc. | 3,670,528 | 1.13 x 235 | 1 | 36 |
| 10 | OPTAGE Inc. | 3,002,112 | 232 | 3 | 68 |
| 11 | NTT DOCOMO, INC. | 2,682,880 | 1.36 x 233 | 1 | 1,251 |
| 12 | NTT PC Communications, Inc. | 2,621,952 | 1.56 x 233 | 1 | 461 |
| 13 | FreeBit Co.,Ltd. | 1,953,536 | 233 | 1 | 410 |
| 14 | IDC Frontier Inc. | 1,919,488 | 234 | 1 | 334 |
| 15 | FUJITSU LIMITED | 1,693,696 | 232 | 3 | 196 |
| 16 | TOKAI Communications Corporation | 1,639,936 | 1.31 x 235 | 1 | 194 |
| 17 | NTT-ME Corporation | 1,628,416 | 242 | 1 | 50 |
| 18 | Chubu Telecommunications Company, Inc. | 1,410,048 | 233 | 1 | 75 |
| 19 | Asahi Net | 1,277,952 | 1.13 x 235 | 1 | 64 |
| 20 | SAKURA Internet Inc. | 1,020,416 | 1.13 x 236 | 4 | 119 |