VAT registration number (VAT number)
It narrows the field to a shortlist. No rule in this engine decides a pair on it.
Unique within: One tax regime. The United Kingdom and the 27 EU member states each run their own shape, their own rules about groups, and their own policy on what a validation service will disclose.
What your VAT number column does in Entity Bind
A VAT number never settles a pair here, and it does two other jobs well. It fetches a shortlist of candidates to compare, which is what a blocking key is for, and it is one of the five facts that can corroborate a country-scoped registration-number agreement — alongside domain, phone, postcode and incorporation date. Send it as `vat_number` and it comes back on the CSV export. It is never a tier, never a headline rate and never decisive on its own. The buildable path is an HMRC check-a-VAT-number adapter, which returns the registered name and address for a UK VAT number and would resolve VAT the way company numbers resolve: through the authority, rather than through an accuracy claim.
Your own column will carry gaps and typos the specimen does not, and a few hundred rows will show how much of your file it still settles.
Start freeOn this page
Issuer, shape and a specimen
Every row below is checkable in another tab: the body that assigns the identifier, the exact shape including any check digits, and a specimen value. Where we hold a value we have verified against the issuing body, the specimen is that value; where we do not, it is a shape, labelled as one.
- Issued by
- The national tax authority — HMRC in the United Kingdom, and each member state's own administration in the European Union. Not a company register, and that is the root of everything below.
- Unique within
- One tax regime. The United Kingdom and the 27 EU member states each run their own shape, their own rules about groups, and their own policy on what a validation service will disclose.
- Format
- In the United Kingdom, GB followed by nine digits, extending to twelve for a branch registration, with the GD and HA prefixes reserved for government departments and health authorities. In the European Union, a two-letter country code followed by a national block whose length and character set differ in every member state — which means there is no single VAT format to validate against, only twenty-eight of them.
- What one value identifies
- A registration for tax, which is not the same unit as a company. A VAT group registers several legal entities under one number, and a company can be registered in several member states at once.
- Specimen
- Shape only: GB000000000, with three more digits for a branch registration. HMRC's check-a-VAT-number service confirms a real one, and we have not verified a specimen against it for this page.
What goes wrong with VAT number
The failure modes that decide whether this column is worth sending, and what each one costs you once it turns up in a live file. Worth reading before you plan an integration around the column.
- 01
Tested as a matching tier and refused on the evidence, recorded on 2026-08-29. The next three entries are what that test found.
- 02
The United Kingdom publishes no lawful bulk name-to-VAT source, so a UK VAT tier could not be measured at all. That is the first half of the reason it is not sold.
- 03
The Czech ground truth built to substitute made the second half worse rather than better. 314 rows were drawn from the Czech ARES register, 25 of 25 spot-verified against the live register with the licence documented — and every one of them showed that a Czech legal person's DIČ is literally CZ followed by the company number, 314 times out of 314. A VAT tier measured on that population would be the identifier tier wearing a different column heading, and carrying the result to the United Kingdom would be a claim about a population nobody had measured.
- 04
Group VAT makes the non-decisiveness structural rather than incidental. Czech group registrations carry a CZ699 prefix, live in a separate register field, and map one-to-many — ČSOB and Hypoteční banka were observed live on one number. A group VAT number therefore names several legal entities by design, so it cannot decide a pair even in principle.
- 05
The EU validation service validates a number you already hold and cannot enumerate. It is reproducible but not linkable — a caller can reissue the identical request and get the identical answer, but there is no URL to open, which is materially weaker than a record-level citation. Several member states return dashes for the name and address as national policy, and storing what it does return is blocked here on an unfinished legal read.
- 06
The scorer carries VAT feature keys in its contract and holds them at zero, with no labelled support. Nothing about a VAT number moves a score today.
Internal fixtures only. The historical 2026-08-29 per-tier recording covers 317 GB companies with identifier-rich arrivals seeding the catalogue first; the context tier includes country and registered-town prose. Its legacy replay has no full-prompt-verified calls and cannot certify current calibration. The September 5 CI reports cover 1,176 labelled pairs and 705 records over 250 companies using offline stubs. These are not independent customer holdouts or live production validation; the 99% minimum-input product target remains unmet. Scope is company and organisation identity only — not people, vessels, bank-account ownership, sanctions or emissions. Results may not be used for eligibility decisions about individuals, including employment, credit and tenancy.
If one of those is already in your file, a sample turns it into a number of rows instead of a suspicion.
Start freeThe other identifiers on a company record
4 of the 8 settle a pair on their own; the other 4 narrow the field and hand the decision on. If your file carries more than one of them, the question worth settling is which one is doing the work.
LEI
Decides a matchLegal Entity Identifier
Company number
Decides a matchCompany registration number
CIK
Does not decideCentral Index Key
Ticker
Does not decideExchange ticker symbol
SIREN / SIRET
Decides a matchSIREN and SIRET
D-U-N-S
Decides a matchData Universal Numbering System number
EUID
Does not decideEuropean Unique Identifier
Or try your own rows: create your Free workspace and upload a company CSV to inspect the decisions and receipts. Where a further column would settle an unresolved row, it names that column; contact us for an assisted review.
Start freeWhere VAT number shows up elsewhere
The rest of the answer, on the shelves that hold it. Each card names its own — a register, a definition, a guide or a comparison — and opens on the page that carries it at length.
- Also listed byNorwayBrønnøysund's Enhetsregisteret is the only register here publishing a telephone number, one of two publishing a website, with three insolvency flags.
- DefinitionVAT numberA VAT number is a tax registration identifier issued by a national tax authority, checkable against the EU's validation service for member states, and a strong but imperfect proxy for company identity.
- DefinitionBlockingBlocking is the technique that makes entity resolution affordable by comparing each record only against a small set of plausible candidates instead of against every other record.
- DefinitionAbstentionAn abstention is a first-class 'we do not know' returned instead of a match: the record comes back unresolved, with a ranked shortlist, a typed reason and the column that would have decided it.
- GuideCompany identifiers explainedCompany number, LEI, CIK, ticker, SIREN and SIRET, DUNS, VAT, EUID and ISIN. What each identifies, who issues it, what it does not guarantee, and which ones actually decide a match.
- GuideKYB data requirementsWhat a know-your-business onboarding flow actually needs, field by field, and which step is identity resolution. Explicitly not a screening, scoring or eligibility tool.
Sources
The bodies and records this page quotes about VAT number, each with the caveat that travels with it.
- HMRC, “Check a UK VAT number”
Confirms a UK VAT number one at a time. There is no lawful bulk name-to-VAT source in the United Kingdom, which is why no UK VAT tier could be measured.
- VIES on-the-Web, European Commission
The EU's VAT validation service. It confirms a number you already hold and cannot be searched by name, and several member states return no name or address.
- ARES, the Czech register of economic subjects
The register the 314-row Czech substitute population was drawn from. Its REST endpoint carries no licence statement, so it is read as pass-through and nothing from it is stored.
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Questions about VAT number
Can I resolve a company from its name and VAT number?
Not as a measured input shape. We tried to measure it and refused to sell it on the result. The United Kingdom publishes no lawful bulk name-to-VAT source at all, so there was nothing to measure a UK tier against. The Czech register was built as a substitute and demonstrated that a Czech legal person's VAT number is literally the country code followed by the company number — 314 of 314 rows — so a tier measured there would be the identifier tier renamed, and carrying the result to the United Kingdom would be a claim about a population nobody had measured. Send the VAT number anyway: it retrieves candidates and it corroborates. It just does not decide.
Do you validate VAT numbers?
Not today, and what validation would buy is narrower than it sounds. The EU validation service checks a number you already hold and cannot be enumerated from a name, so it is a corroboration route rather than a discovery route. It is also reproducible but not linkable — you can reissue the request and get the same answer, but there is no record-level URL to cite — and several member states return dashes for the name and address as a matter of national policy. It is a planned source here, and storing the name and address it returns is blocked on a legal read that has not been done.
Is a VAT number a unique identifier for a company?
No, in two directions at once. A VAT group registers several legal entities under one number by design — Czech group registrations carry a distinguishing prefix and were observed live mapping one number onto two banks — so one VAT number can name several companies. And a company trading across the European Union can hold registrations in several member states, so one company can carry several VAT numbers. Either property on its own would stop a VAT number deciding a match; both together are why it is a blocking key and a corroborating fact here, and nothing more.