How is a CVR number validated?

Multiply the 8 digits by the weights 2,7,6,5,4,3,2,1, add the products, and the CVR is valid if the sum is divisible by 11 (the remainder modulo 11 is 0). The final weight of 1 applies to the check digit itself.

How many digits is a CVR number?

A Danish CVR number is exactly 8 digits. The last digit is a check digit derived from the first seven, and the full number identifies a registered Danish business.

Is the CVR the same as the Danish VAT number?

They are closely linked. A Danish VAT number is normally the CVR number prefixed with the country code DK, so a valid CVR underpins the VAT registration.

Does a valid checksum confirm the company exists?

No. A valid checksum only confirms the number is internally consistent. To confirm the company is registered and active, look it up in the official CVR registry.

Is my CVR number sent anywhere?

No. The validation runs entirely in your browser in JavaScript, so the CVR number never leaves your device.

Denmark CVR Validator

A CVR number (Det Centrale Virksomhedsregister) is the 8-digit identifier issued to every business registered in Denmark. It anchors invoicing, VAT, and public procurement records, so confirming a CVR is well-formed before relying on it prevents costly data-entry errors. This validator runs the official modulus-11 check directly in your browser.

How it works

A CVR number carries a built-in check digit verified with a weighted modulus-11 algorithm:

Take all 8 digits, including the check digit.
Multiply them by the positional weights 2, 7, 6, 5, 4, 3, 2, 1.
Add the products to get a weighted sum.
The CVR is valid if sum mod 11 is 0.

Because the final weight is 1 and multiplies the check digit itself, the algorithm self-corrects: only a check digit that makes the whole sum divisible by 11 will pass.

Example

For the CVR 35 25 41 19, multiplying each digit by its weight and summing the products yields a total that divides evenly by 11, so the remainder is 0 and the number passes the checksum.

Notes

A valid checksum confirms structural correctness, not registration. A company could be deregistered yet still have a checksum-valid CVR, so always confirm active status in the official CVR registry for compliance work. Everything is computed locally, so the CVR you enter never leaves your browser.