With its decision of 3.3.2016 the Swiss Federal Supreme Court held, that it is possible to register joint signatures with certain restrictions. The Commercial Register therefore must register not only which persons have joint signature but - if the company asks for it - also who can sign with whom and in what combination a signature is not valid.
Nevertheless a company or board of directors has to be careful about a signature-regime that is to complicated and has to be adopted to often. If the registered signatures are not up to date and persons without signature regularly sign for the company, it might be possible that they can conclude a legally binding contract for the company. If this damages the company the board of directors can be held personally liable.