Yes, this is possible. SwissVPN is a prepaid service by default, which means, when purchasing you select a fix contract duration between 1 and 12 months. After this period your contract terminates automatically and without cancellation. If you wish to use your account for an extended duration, you can renew your contract by clicking Buy and enter your username in the following payment window.
If you want to avoid this manual renewal process, you can select auto renewal in the payment window. We will then auto renew your account automatically on a monthly basis. This feature is available for credit card payment using American Express, Mastercard and VISA.