What this page checks, and what not. It checks only the format and the check digit. It does not tell you whether a company exists, whether the number belongs to the company you have in mind, or whether it is liable for VAT. For that, search the official UID register (uid.admin.ch).
How the check digit works
A Swiss UID has the form CHE followed by nine digits. The ninth digit is a check digit. Federal Statistical Office (FSO/BFS) describes the structure of the UID on its UID pages; the register itself is run at uid.admin.ch.
- Multiply the first eight digits by the weights 5, 4, 3, 2, 7, 6, 5, 4.
- Add the eight products.
- Divide the sum by 11 and take the remainder.
- Check digit = 11 minus the remainder. If the result is 11, the check digit is 0. If it is 10, no valid UID exists for those digits.
Example with the made-up digits 10000001: 1·5 + 0·4 + 0·3 + 0·2 + 0·7 + 0·6 + 0·5 + 1·4 = 9. Remainder of 9 divided by 11 is 9. 11 − 9 = 2. The number is CHE-100.000.012. This is a test number, not a real company.
How to write it on an invoice
The normal form is CHE-123.456.789, with hyphen and two dots. If the supplier is registered for VAT, the invoice shows the UID with the note MWST (German), TVA (French) or IVA (Italian), for example «CHE-123.456.788 MWST». If you are not in the VAT register, do not add this note. Details are in our guide Swiss invoice requirements.
Test numbers
These numbers were generated with the method above. They are not real companies.
| Number | Result |
|---|---|
| CHE-100.000.012 | valid |
| CHE-123.456.788 | valid |
| CHE-200.000.024 | valid |
| CHE-123.456.789 | wrong check digit |
| CHE-100.000.013 | wrong check digit |
| CHE-300.123.450 | cannot exist (check value 10) |