Basic health insurance:
For mandatory basic insurance, the following provisions apply: your application to a new company is provisional until it receives confirmation of your cancellation from your current insurer. This way, no one has to pay double premiums for basic health insurance if they missed the cancellation deadline.
Applications for supplemental insurance are legally binding, which means that, after submitting the signed offer, the applicant is bound for 14 days (Insurance Policies Act, Art. 1). Should he be rejected or only accepted with certain restrictions, the applicant is freed once again. However, if a medical examination is required, the applicant will even remain bound for 4 weeks. There is no right of withdrawal as is the case for door-to-door sales, unless the contract explicitly states the right of withdrawal.
Double insurance is possible with supplemental insurance: if an applicant is accepted but has missed the cancellation deadline for his former insurance provider, he has to pay both premiums. The new insurance company may agree to postpone or suspend coverage, but is not obliged to do so.