The UID/IDI number: what it is for and how to obtain it

Anyone starting a business in Switzerland soon comes across an acronym that appears on every official document: UID (Unternehmens-Identifikationsnummer), IDI in Italian. It is the business identification number, the unique “licence plate” that follows every economic entity from the commercial register to VAT. Understanding what it is and how it works avoids confusion with other identifiers and speeds up every procedure.

What the UID/IDI number is

The UID is a unique and permanent identifier assigned to every active business in Switzerland: corporations, sole proprietorships, partnerships, associations, public bodies. The idea is to have a single number that identifies the entity across all administrations, replacing the old fragmentation in which each office used its own code.

The format is recognisable: the prefix CHE followed by nine digits, usually written in groups (for example CHE-123.456.789). The initial letters recall Switzerland; the digits are a sequential number with a final check digit, which serves to validate the correctness of the code.

What it is for

The UID number is the key that links your business to several registers and procedures:

• Commercial register: it identifies the registered company.
• VAT: when the company is liable, the UID becomes the basis of the VAT number, with the addition of the wording that signals registration (typically the suffix “VAT”/“MWST”).
• Statistics and administrations: customs, social insurances and other offices use the same identifier.

The advantage is consistency: a single number reduces matching errors between cases and lets the authorities immediately recognise the entity.

UID and VAT number: don’t confuse them

This is the most frequent misunderstanding. The UID is the business’s base number; the VAT number is the same identifier to which the mention of liability for value added tax is added. In practice:

• Every registered business has a UID.
• Only businesses liable for VAT also use the UID in the “VAT” version.

Having a UID therefore does not mean being automatically registered for VAT purposes: VAT registration follows its own rules, tied above all to exceeding the turnover threshold. The UID nonetheless stays the same, before and after any VAT registration.

How it is obtained

The good news is that, in most cases, you do not have to request it separately. The UID number is assigned automatically when the business is registered with the competent authority — typically at the time of entry in the commercial register for corporations.

In short:

• Companies (GmbH, AG): the UID is assigned upon registration in the register. It therefore already appears in the extract and in the incorporation deeds.
• Sole proprietorships and unregistered activities: the UID is generated when the business comes into contact with an administration that registers it (for example when filing a notification or becoming subject to an obligation).

Once assigned, the number stays the same for the entire life of the business: it does not change with a relocation of the registered office nor with an ordinary statutory amendment.

Where it must be shown

The UID number must be shown on the business’s official documentation. In particular, those liable for VAT must correctly display their number on invoices, so that clients can identify them and, where entitled, recover the input tax. Showing it clearly on letterhead, contracts and invoices is a sign of order and compliance.

In short

• The UID/IDI is the business’s unique identifier in Switzerland, in the format CHE + nine digits.
• It links the company to the commercial register, VAT and administrations.
• It does not coincide with VAT registration: the latter adds a mention to the same number.
• For companies it is assigned automatically upon registration in the register and stays unchanged over time.

How we help you

We manage the incorporation of your company from the notarial deed to registration in the register, so you obtain the UID smoothly and start with your documentation in order. Incorporate with our Corporate Division.