Sole signature (Einzelunterschrift)

How sole signature works under Swiss law

A Swiss company acts through the people entered in the commercial register with signing authority. For a stock corporation, Art. 718 CO gives each member of the board of directors sole authority to represent the company unless the articles of association or the organisational regulations provide otherwise. Many boards regulate it, and the register records the result for each person: mit Einzelunterschrift, mit Kollektivunterschrift zu zweien, or no signing authority at all. For a GmbH, Art. 814 CO applies the same logic to the managing directors (Geschäftsführer).

A person with sole signature binds the company with their signature alone. Art. 718a CO sets the scope: any legal act the company's purpose may entail. Internal limits, such as a board rule that contracts above CHF 50,000 need prior approval, have no effect on a third party acting in good faith. The restrictions a third party has to accept are the ones entered in the register: a joint signature or a limitation to the head office or to a branch.

Art. 718 para. 4 CO requires that an AG can be represented by one person resident in Switzerland, who must be a board member or an executive officer (Direktor). Art. 814 para. 3 CO sets the same rule for the GmbH, where that person must be a managing director or an executive officer. A Swiss resident with sole signature meets the requirement alone. Register offices also accept a Swiss resident with joint signature by two, provided a second signatory resident in Switzerland can sign with them.

Sole signature and joint signature in practice

With sole signature, one signature is enough for a contract, a bank instruction or a notice of termination, where joint signature by two needs a second authorised name. Many companies combine both: the chair and the CEO sign alone, while the other board members and senior staff sign jointly. In an owner-managed GmbH, the owner usually holds sole signature, and the owner of a sole proprietorship nearly always appears as Inhaber, mit Einzelunterschrift.

Einzelprokura

A Prokurist holds a commercial power of attorney under Art. 458–460 CO and signs the business name "per procura", usually shortened to "ppa.". With Einzelprokura the Prokurist signs alone. The scope is narrower than a board member's: a Prokurist may carry out every act the business may involve, but may sell or mortgage real estate only with express authority (Art. 459 para. 2 CO).

How it appears in the register and in SHAB notices

Each person entry in a register extract ends with the signing authority. The SHAB notice published when someone joins, changes role or leaves repeats that wording in the language of the canton: mit Einzelunterschrift in Zurich, avec signature individuelle in Geneva, con firma individuale in Ticino. A move from joint to sole signature is published as a change to the person entry, with the previous authority in brackets.

What to check when dealing with a company

• Before signing a contract, check on a current register extract that the person signing for the other side holds sole signature. If they sign jointly, ask for the second signature.
• A board member entered without signing authority cannot sign for the company, whatever title they use.
• When one person is the only signatory, that person alone controls what the company commits to. This is common in small GmbHs and useful to know before extending credit.

The guide to signing authority in Switzerland covers the other combinations, and how to check a Swiss company lists the other register facts worth reading.