What is a CVR number in Denmark?

The CVR (Det Centrale Virksomhedsregister) number is the 8-digit company registration number. For VAT it is prefixed with DK, so a Danish VAT number is DK followed by the 8-digit CVR.

How is the Danish VAT check digit calculated?

The eight digits are multiplied by the weights 2, 7, 6, 5, 4, 3, 2, 1 and the products are summed. The number is valid if that sum is exactly divisible by 11 (sum mod 11 equals zero).

Do I need to type the DK prefix?

No. You can enter the number with or without the DK prefix and with or without spaces. The tool strips the prefix and separators before checking the 8-digit CVR.

Does a valid check digit mean the company is VAT-registered?

No. The checksum only confirms the number is internally consistent. To confirm the company is active and VAT-registered, check the CVR registry or the EU VIES service.

Is my VAT number sent to a server?

No. The modulo-11 calculation runs entirely in your browser. Nothing is transmitted, so the tool is safe for business and compliance use.

Denmark VAT Number Validator

The Denmark VAT Number Validator checks whether a Danish VAT number is structurally valid by recomputing the official modulo-11 checksum on the 8-digit CVR. It accepts the number with or without the DK prefix and tells you whether the check digit is consistent — all in your browser.

How it works

A Danish VAT number is the prefix DK followed by the 8-digit CVR (Det Centrale Virksomhedsregister) number. The CVR carries a built-in modulo-11 check digit, which is the mechanism that catches transposed or mistyped digits.

The tool multiplies the eight digits, left to right, by the weights [2,7,6,5,4,3,2,1], sums the products, and divides by 11. If the remainder is zero, the number is internally consistent and the check passes. The eighth digit is the check digit, so a non-zero remainder means at least one digit is wrong.

Example

For DK 12345678 the tool computes the weighted sum, takes it modulo 11, and reports the remainder, which must be 0 for the number to be valid. Entering the same digits without the prefix, or with spaces, produces the same result because separators are stripped first.

Notes

A valid check digit confirms the CVR is internally consistent under the modulo-11 rule — it does not confirm the company is currently VAT-registered or trading. For live status, check the CVR registry or the EU VIES service before relying on the number for Nemhandel e-invoicing or intra-EU transactions. Everything runs locally in your browser.