B2B & B2c
It is not permissible to perform direct marketing by fax to either corporate or individual subscribers without their prior consent.
Please visit:
http://www.bakom.admin.ch/dienstleistungen/info/00542/00886/00891/index.html?lang=en
It is possible to perform direct marketing by fax if a commercial relationship already exists. The law allows the data controller to use the contact details already provided by the data subject in the context of a sale for direct marketing of their own products or services, provided that the products or services are similar to those previously sold and that a contract between a company and an individual has been formed and has not stopped at the phase of contract negotiations.