What does a Swiss UID look like?

A Swiss UID (Unternehmens-Identifikationsnummer) is the prefix CHE followed by nine digits, conventionally written CHE-XXX.XXX.XXX. For VAT it may carry a MWST, TVA, or IVA suffix, which does not affect the check digit.

How is the UID check digit computed?

Multiply the first eight digits by the fixed weights 5, 4, 3, 2, 7, 6, 5, 4 and sum the products. The check digit is 11 minus (sum modulo 11). If that result is 11 the check digit is 0; a result of 10 means no valid check digit exists and the number is invalid.

Does a valid UID mean the company is VAT-registered?

No. The check digit only confirms the number is internally consistent. A company can have a UID without being VAT-registered. Confirm VAT status through the official Swiss UID register or the MwSt list.

Are the dots and dashes required?

No. CHE-116.281.710, CHE116281710, and CHE-116.281.710 MWST all validate identically. The tool strips formatting and the VAT suffix before checking the nine digits.

Why would a UID fail validation?

The most common causes are a mistyped or transposed digit, the wrong number of digits, or a remainder that produces check digit 10 (which is not allowed). Re-check the nine digits against the commercial registry entry.

Switzerland UID Validator

The Swiss UID (Unternehmens-Identifikationsnummer) is the single business identifier used across the Swiss commercial registry, VAT (MwSt), and federal statistics. Before relying on a supplier’s UID, you can confirm it is internally well-formed using the official modulo-11 check. This validator runs that check entirely in your browser.

How it works

A UID is CHE plus nine digits. The ninth digit is a check digit computed from the first eight:

Strip the CHE prefix, any dots/dashes, and any VAT suffix (MWST / TVA / IVA), leaving nine digits.
Multiply the first eight digits by the fixed weight vector 5, 4, 3, 2, 7, 6, 5, 4.
Sum the eight products.
Compute check = 11 - (sum mod 11).
If check is 11, the check digit is 0. If check is 10, no valid check digit exists, so the UID is invalid. Otherwise the ninth digit must equal check.

Example

Validate CHE-116.281.710. The first eight digits are 1 1 6 2 8 1 7 1.

Weighted sum: (1x5)+(1x4)+(6x3)+(2x2)+(8x7)+(1x6)+(7x5)+(1x4) = 5+4+18+4+56+6+35+4 = 132. 132 mod 11 = 0, so check = 11 - 0 = 11, which maps to check digit 0. The stated ninth digit is 0, so the UID is valid.

Notes

A valid check digit confirms structure, not VAT registration. For legal certainty, look the UID up in the official register. All processing here is local — nothing is transmitted.