IIJ Domain Service is a domain registration service from Internet Initiative Japan (IIJ), one of the pioneers of Japan’s internet infrastructure. It supports business JP domains like .co.jp, standard .jp domains, and common extensions like .com and .net, with domain management and DNS handled as separate services for flexible setup.

Contracts are arranged through custom quotes with monthly billing, reflecting the service’s focus on larger organizations. DNS runs through the separate IIJ DNS Platform Service, which carries ISMAP certification (a government cloud security standard required for public-sector procurement in Japan). Support includes around-the-clock incident response and year-round technical help.

The DNS platform supports ANAME records, which let users point their main domain (like example.co.jp) to cloud services or CDNs without workarounds that break DNS rules.

DNSSEC adds a layer of protection against DNS tampering. When using IIJ’s DNS platform, zone signing and registry updates are handled automatically with no manual steps needed.