Who are the largest registered agents in the US?

The largest registered agent in the US is CT Corporation, a Wolters Kluwer company, named as the registered agent on at least 3.0 million business entities across the state registries. Corporation Service Company (CSC) is second at about 2.3 million. No federal agency publishes this ranking, so the only way to build it is to count the registered-agent field across every state registry that records one.

Who is the largest registered agent in the US?

Ranked by the number of US entities that name them, the ten largest registered agents are two century-old incumbents, two newer discount services, and a middle tier of national filing companies. The figures below count distinct entity records in each firm's own name plus the names of the subsidiaries it operates under.

CT Corporation goes back to 1892, when it was founded as The Corporation Trust Company. Wolters Kluwer bought it in 1995 and still operates its Delaware service under the old Corporation Trust name, at 1209 North Orange Street in Wilmington, an address that is itself the registered agent for hundreds of thousands of entities (Wikipedia). CSC, founded in 1899 and privately held in Wilmington, is the other old-line agent (Wikipedia).

The count is a floor. It matches names conservatively and covers the 49 registries that publish a registered agent, so the true figure for each firm is somewhat higher, not lower.

Why is there no official ranking?

Because there is no national registry to read it from. A registered agent is filed with a state, not the federal government, so the agent data lives in 50 separate registries, one per state. To rank the firms you have to pull all of them and reconcile the names, which almost no one does.

The pages that do try fall into two camps. Most "best registered agent" articles rank firms on price and features, not on how many clients they have. The handful that claim a size ranking are thin: the most cited public count covers four small states and dates to 2014. So the question has an answer that no one has published with current, national numbers.

The corporate-family structure adds to the confusion, because the same firm files under several names. Wolters Kluwer owns three of the names in the table: CT Corporation, National Registered Agents (NRAI), which it acquired in 2011, and BizFilings (Compliance Week). CSC owns The Company Corporation. The table above rolls each brand up to its parent, which is why CT Corporation leads: the CT name alone is on 2,333,772 entities, and NRAI and BizFilings add the rest.

Is the "Big Four" still the Big Four?

Not on entity count. Registered-agent comparison sites have long grouped the field into a "Big Four" of CT, CSC, NRAI, and InCorp Services. Two of those four have been passed.

National Registered Agents, now a Wolters Kluwer brand, is named on about 448,000 entities on its own. InCorp Services is named on about 245,000. Both sit behind two firms the older lists rarely mention: United States Corporation Agents, a discount service named on about 1.1 million entities, and Registered Agents Inc, named on about 1.0 million. Registered Agents Inc built its volume in low-cost, privacy-oriented formation states like Wyoming and now appears in nearly every registry.

The incumbents still lead on the largest companies. CT and CSC each publicly claim most of the Fortune 500 as clients. But the Fortune 500 is 500 entities, and the volume in these numbers is ordinary LLCs, where the discount agents compete hard on price.

How concentrated is the registered agent market?

Less than the top of the list suggests. About 70.6 million of the roughly 91.6 million US entities on record name a registered agent. The single largest firm is named on about 4% of them. The ten largest together are named on 9.6 million, about one in seven.

The other 61 million or so are spread across thousands of smaller national agents, regional and single-state agents, law firms, and owners who serve as their own agent. So while two firms clearly lead, no firm is anywhere near a majority, and the long tail holds most of the market. A filter that only knows the big commercial names would miss the agent for most US entities.

How do you look up or count registered agents yourself?

For a single entity, read its record in the state where it is registered: the registered agent is public in 49 of the 50 registries, listed with a name and a service address. For counts across states you need the registries normalized into one schema, because each one writes the same firm's name differently.

That normalized layer is what GovFiles provides. The registered agent is exposed as a party with the role registered_agent, and the /v2/officers/search endpoint filters on it, so you can pull every entity that names a given agent. The numbers in this post come from the same data as a bulk export across all 49 registries.

# Every entity that names CSC as registered agent, one page at a time
curl -s -X POST 'https://api.govfiles.dev/v2/officers/search' \
  -H "X-API-Key: $GOVFILES_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"q": "Corporation Service Company", "role": "registered_agent", "limit": 50}'

{
  "summary": { "total_matches": 10000, "total_is_capped": true },
  "results": [
    {
      "officer": {
        "type": "company",
        "name": "Corporation Service Company",
        "roles": [{ "kind": "registered_agent" }]
      },
      "company": {
        "jurisdiction_code": "us_ak",
        "entity_number": "10000001",
        "legal_name": "PLATINUM HOME MORTGAGE CORPORATION",
        "status": "active"
      }
    }
  ]
}

The search endpoint reports a match count only up to 10,000, which is fine for a lookup but not for a count in the millions. Ranking the firms is a job for the full dataset, where you group the whole registered-agent field at once.

Frequently asked

Who is the largest registered agent in the US? CT Corporation, a Wolters Kluwer company, is the largest. Counting across the state registries, it is named as registered agent on at least 3.0 million US business entities, including its National Registered Agents and BizFilings brands. Corporation Service Company (CSC) is second at about 2.3 million. Both firms were founded in the 1890s.

Is CT Corporation bigger than CSC? Yes, by entity count. CT Corporation and its sibling Wolters Kluwer brands are named on at least 3.0 million entities across 49 registries; CSC and its subsidiary The Company Corporation are named on about 2.3 million. The gap is real but not large, and both lead the field by a wide margin over everyone else.

How concentrated is the registered agent market? Less than it looks. About 70.6 million US entities name a registered agent. The single largest firm accounts for roughly 4% of them, and the ten largest together account for about one in seven. The rest are spread across thousands of smaller national and regional agents and individuals.

Is registered agent information public? Yes. The registered agent is filed with the Secretary of State and is part of the public entity record in 49 of the 50 state registries. Both the agent's name and its service address are public. Building a national count means reading and normalizing those 49 separate registries.