This question comes up in almost every first conversation, usually phrased as though there is a rule. There is not a rule. There is a trade-off, and which side of it you land on depends on facts about your company rather than facts about search engines.

The short version: you do not need a .co.jp domain to rank in Japan. There are situations where having one is clearly right, and situations where it is an expensive way to make your SEO harder. Below is how to tell which one you are in.

What .co.jp actually is

.co.jp is not a marketing domain you can buy. It is a restricted second-level domain under Japan’s country-code TLD, administered by JPRS, and it carries real eligibility requirements:

  • The registrant must be a company registered in Japan — a legal entity incorporated under Japanese law. A foreign company without a Japanese subsidiary or branch does not qualify.
  • One per company. A registered entity may hold exactly one .co.jp. This is the constraint that gives the domain its meaning: a .co.jp address is, by construction, a one-to-one identifier for a Japanese corporate entity.
  • Registration requires documentary proof of incorporation — typically the certificate of registered matters (履歴事項全部証明書, rireki jikō zenbu shōmeisho) from the Legal Affairs Bureau, dated recently.

There are adjacent options. General-purpose .jp domains are open far more widely, though the registrant is still expected to have a contactable presence in Japan, and you can hold as many as you like. Because they are unrestricted, they do not carry the “this is a registered Japanese company” implication that .co.jp does. .ne.jp, .or.jp and the rest are for other organisation types and are not relevant here.

So the first question is not “should we get a .co.jp” — it is “do we have a Japanese legal entity”. If the answer is no, the decision has already been made for you, and the rest of this article is about doing well without one, which is entirely possible.

Does Google treat it as a ranking factor?

Not in the way people mean when they ask.

A country-code TLD is a strong and unambiguous geotargeting signal. Google treats a ccTLD as indicating the site is intended for that country, and that association is essentially automatic — you do not configure it, and you cannot really override it. So .co.jp does tell Google, clearly and permanently, that this site is for Japan.

But geotargeting is not relevance. It helps decide which audience a page is a candidate for; it does not decide whether the page is a good answer. A well-researched Japanese page in a subdirectory on a strong global domain will routinely outrank a thin page on a .co.jp, because the thing being compared is the page, not the suffix.

It is worth noting that Google has retired the manual country-targeting setting that used to live in Search Console’s International Targeting report. For a generic domain, geotargeting is now inferred from signals — language, hreflang, content, links, server and business location — rather than declared. That has made the ccTLD’s built-in clarity slightly more valuable than it was, but it has not turned it into a ranking factor.

The real trade-off: consolidation versus signalling

Here is the substance of the decision.

A subdirectory (example.com/ja/) keeps everything in one place. Whatever authority your global domain has accumulated — years of links, brand mentions, established crawl behaviour — the Japanese section starts inside it rather than beside it. For a company with a genuinely strong global domain, this is a large, immediate, real advantage, and it is the single strongest argument in the subdirectory’s favour.

A separate .co.jp starts from zero. New domain, no link history, no established trust. Everything the global domain took a decade to earn has to be re-earned in Japan, from Japanese sources. That is not impossible — it is how every Japanese company’s site got where it is — but it is a multi-year programme, and it needs a budget line, not just a domain registration.

There is also an operational cost that gets underestimated. Two domains means two CMS setups (or one with awkward multi-domain support), two analytics properties, two Search Console properties, two release cycles, two sets of technical debt, and a cross-domain hreflang cluster that has to stay reciprocal across teams that do not share a sprint board. We see broken hreflang far more often on split-domain setups than on subdirectories, and the reason is organisational rather than technical.

What .co.jp genuinely buys you

Not rankings. Credibility — with people.

In Japanese B2B, particularly at the enterprise end and in conservative sectors like finance, government-adjacent work, healthcare and heavy manufacturing, a .co.jp address reads as evidence that you are a real, registered, locally accountable company. It appears on business cards, in email addresses, on the corporate registry checks that procurement teams genuinely run. Its scarcity — one per entity, proof of incorporation required — is exactly what makes it meaningful.

That matters to SEO indirectly and unevenly. If your buyers are procurement committees at large Japanese corporates, the domain contributes to whether they take the enquiry seriously. If your buyers are engineers or startup founders who have already heard of you, it contributes very little. Both of those are real markets and they weigh this differently.

When a subdirectory is the better call

  • Your global domain has meaningful accumulated authority.
  • You do not yet have a Japanese legal entity, or you have one but it is small and new.
  • You are testing the market and want to know whether Japanese organic demand exists before committing.
  • Your product is bought by practitioners rather than by procurement committees.
  • You have one web team, one CMS and no appetite for running a second stack.
  • Your Japanese content programme is going to be modest in its first year.

For most international companies entering Japan for the first time, this is the correct answer. It is also reversible: a subdirectory can be migrated to a .co.jp later, and doing it later means migrating something that already works.

When .co.jp is worth it

  • You have an established Japanese entity with local staff, and Japan is a named market with its own budget rather than an experiment.
  • Your buyers are large Japanese enterprises, financial institutions or public-sector-adjacent organisations where corporate legitimacy checks are part of the process.
  • The Japanese business needs genuine operational independence — its own product line, pricing, contracts, support and content calendar — and the global site cannot sensibly represent it.
  • You are prepared to fund Japanese-language authority building as a standing programme, not a project.
  • Your global domain is not especially strong, so there is less to give up by starting separately.

Notice that most of these are business conditions, not SEO conditions. That is the honest shape of this decision.

The subdomain middle ground

ja.example.com is sometimes proposed as a compromise. In our experience it mostly collects the disadvantages of both: it does not carry the local credibility of a .co.jp, and it introduces a separation that consolidation-minded teams then have to reason about.

There are legitimate reasons to choose it — a different technology stack for the Japanese site, a hard organisational boundary, a CDN or hosting constraint — and if one of those applies, a subdomain is fine and can rank perfectly well. It is a sound answer to an infrastructure question and a weak answer to a marketing one.

What actually drives Japanese rankings

If you are choosing a domain in the hope that it will do the work, it is worth being direct about where the work actually is. Roughly in order of impact:

  1. Whether your pages address real Japanese search demand — which is a keyword research and content problem, not a domain problem, and the one most often skipped. See Why Translating Your Website Is Not Japanese SEO.
  2. Whether the content is good enough for the results page it is competing on — depth, specificity, and the credibility signals Japanese B2B buyers expect.
  3. Whether the site is technically accessible and correctly annotated — crawlable, indexable, self-canonical, with working hreflang.
  4. Whether Japanese-language sources reference you — industry media, associations, partners, comparison platforms.
  5. The domain.

We are not saying the fifth item is nothing. We are saying that companies who get the first four right rank in Japan on example.com/ja/, and companies who get them wrong do not rank on example.co.jp either.

If you already have a dormant .co.jp

This is a common situation. A distributor registered one years ago, or the Japanese subsidiary built a small site that has drifted out of date while the global site moved on. You now have two Japanese-facing properties competing with each other, usually with overlapping content and no hreflang between them.

That is worth resolving deliberately rather than leaving. Either consolidate — pick one, redirect the other, keep the redirects permanently — or commit to both with a clear division of purpose and correct annotations. What you should not do is leave two half-maintained Japanese sites splitting the same signals, which is the outcome that does measurable harm.

If you are weighing this up for a specific site, it is one of the first things we work through in a Japan market entry engagement, and it is usually a shorter conversation than people expect once the entity question is settled. Tell us where you are and we will give you a straight answer.