Entity number lookup directory: build your own crosswalk

One company can have five registers and five numbers, none related. A supplier list of 200 companies across several states and a couple of countries carries several hundred identifiers in practice, issued by dozens of offices.

The entity number lookup directory that actually works is not a list of offices. It is a crosswalk: your own table showing, for each company, which office issued which number and how you confirmed it.

This page is how to build and keep that crosswalk. The offices themselves are found through the state entity directories pillar.

What to take away

Why the crosswalk has to be yours

No register cross-references another. A state entity record omits the company's other-state number, its number on a foreign national registrar, and its tax identifier.

A company formed in Delaware and registered to do business in Texas has one number on the Delaware Division of Corporations register and a different one with the Texas Secretary of State, and neither page shows the other.

A national registrar omits the numbers of the company's foreign subsidiaries. Only a hand-built table, drawn from the company's own documents, places these numbers side by side.

That means the crosswalk is not a lookup you copy from anywhere. It is an assertion, per row, that this number on this register belongs to the same legal entity as that number on that register, and the assertion needs a source.

The shape of the table

One row per register per company. A company registered at home and in four other states has five rows under one company key. Its parent abroad is a different company key with its own rows, and the parent-subsidiary relationship is a separate table again, because registers do not record it either.

The "linked by" column is the whole point

Numbers from two different registers can share a company key only if something says they are the same entity. Acceptable proof: the company's own foreign qualification filing naming the home state and home number; a company-supplied certificate; a contract quoting both numbers; or the company's accounts naming its subsidiaries.

Unacceptable: the names look the same. Same-looking names across registers are the failure the crosswalk exists to prevent, as the entity number lookup pillar sets out.

If a row has nothing in "linked by", it is a candidate, not a link. Mark it so.

Identifiers that do not belong in the crosswalk as links

Some numbers are useful to store and useless as evidence of identity across registers.

A tax identifier is issued by a revenue agency, not the entity register. The IRS page on getting an employer identification number shows the split: a different body, a different application, a different purpose.

It goes to the taxpayer, which may or may not match one registered entity. Store it in its own row, with the tax authority as the register, and do not use it to join state rows.

A license number identifies a license, which can be held by a person or an entity and can outlive or predate the entity. Same treatment.

An identifier issued for a specific program is designed to be stable within that program and nowhere else. The Unique Entity Identifier (UEI) assigned in SAM.gov, the federal contracting system's entity registration, is the clearest example: genuinely unique, genuinely useful, and populated from what the entity itself submitted. Store it; confirm the underlying registrations anyway.

Numbers that change under you

Registers occasionally reissue identifiers: on conversion from one entity type to another, on domestication into a state, on a system migration. When that happens, do not overwrite the row. Close it with an end date and add a new row with the new number and a "linked by" pointing at the filing that made the change.

The filing history is where that filing will be, and it is the only place the change is documented. Old documents will quote the old number for years, and the closed row is what lets you recognize them.

Keeping it current

The crosswalk is only as good as its confirmation dates. Re-confirm each row when the company's periodic report on that register falls due, when you see a status change anywhere, and before any decision resting on the row.

Re-confirming means opening the register, reading the number and name off the page, and updating the date. The registration status on each row is the cheapest early warning that something has moved.

What the crosswalk cannot do

It cannot tell you that a company is sound, that a group is what it claims, or that the person you deal with speaks for any entity in it. It tells you which registers hold which numbers for which legal entity, with a source for each link.

That is a small thing, but it turns a pile of numbers from a dozen offices into something you can query without guessing. It feeds the wider sequence in company verification, which is where the judgments get made.

Common questions

How many rows is too many to keep by hand?

Fewer than people expect. A hundred companies with three registrations each is three hundred rows re-confirmed on a staggered schedule, which is a morning a month. The failure mode is not size; it is letting the confirmation dates go stale so that nobody trusts the table.

Can I buy a crosswalk instead of building one?

You can buy a compiled dataset, and it will be somebody else's judgment about which records are the same entity, usually made by name matching and usually undated. If the join matters, the "linked by" column is the product, and that is the column a purchased file will not have.

What do I do with a company that will not tell me its state of formation?

Record that. It is a legitimate thing to ask for, it appears on the company's own foreign qualification filings where they exist, and a refusal is information about how the rest of the check should be scoped.

Should the crosswalk hold former names?

Yes, with the filing that changed them. Old invoices, contracts, and credit files quote former names for years, and the crosswalk is the only place anyone will be able to resolve them.