Romania CUI / CIF validator
How the CUI / CIF format works
- Format
- RO + 2 to 10 digits
- Example
- RO1234567
Things to watch for
- Length varies from 2 to 10 digits
- This tool checks the format only; the Romanian check digit is not yet validated
^RO[0-9]{2,10}$Romania is the outlier among EU VAT formats: instead of a fixed digit count, “RO” can be followed by anywhere from 2 to 10 digits, as in RO1234567. That’s not sloppy formatting — the digits are the business’s CUI (Cod Unic de Inregistrare, historically also called CIF), a sequential registration number that Romania’s trade registry (ONRC) and tax authority (ANAF) have issued continuously since long before the country joined the EU, so the length simply reflects when a business was first registered.
That variable length is exactly what trips up validation logic built around a single expected count: a genuine, currently active Romanian VAT number can legitimately be as short as 2 digits after “RO”, not just as long as 10. Rejecting a short number as “too short” is a common but incorrect assumption for anyone unfamiliar with how Romania assigns CUI values.
What’s checked here
This validator confirms the “RO” prefix and counts between 2 and 10 digits inclusive, entirely in your browser, with no signup and nothing sent to a server. It’s a length-range-and-prefix check — Romania’s official check-digit calculation on the CUI isn’t run here.
What a pass doesn’t mean
A correctly shaped RO number doesn’t confirm the CUI is currently active for VAT purposes. Confirm through the EU’s VIES lookup or ANAF directly before relying on it for invoicing.
Scope: CUI/CIF format only (2–10 digits) — not check-digit validation or registration status.
Content last reviewed 2026-07-07.
CUI / CIF FAQ
Why does a Romanian VAT number have no fixed digit count?
Because the digits are the business's CUI (Cod Unic de Inregistrare), a sequential registration number assigned over decades of company formations — older or earlier-registered businesses can have as few as 2 digits, newer ones up to 10, all equally valid with 'RO' in front.
Is CUI the same thing as CIF in Romania?
In practice, yes for most current purposes — CIF (Cod de Identificare Fiscala) is the older name still used colloquially, while CUI is the term used since a company-law update; both refer to the same identifying number a business carries for tax purposes.
Does this tool confirm a Romanian VAT number is actively registered?
No — it only checks that 'RO' is followed by 2 to 10 digits. Confirm live registration through the EU's VIES lookup or Romania's ANAF (Agenția Națională de Administrare Fiscală).