When and how can I cancel my PRO or STUDIO license?

You can cancel your subscription within one month after activation or renewal and by doing so you will not be charged anymore. Automatic renewals are month by month. As an example: If you activated your subscription on the 5th of May then it will run till the 5th of June and you can cancel until the 4th of June. Here is how to view, change or cancel your active subscriptions: https://support.apple.com/en-us/HT202039