You can cancel your myCloud Pro subscription at any time online. The cancelation will take effect at the end of the given billing period (30 days). Until the cancelation takes effect, the paid version including all storage and functions will still be available for you to use. Afterwards, your account will automatically be downgraded to the next available subscription (myCloud Standard / myCloud Light). Before the downgrade takes place, you’ll receive an email containing pertinent information. Should you be using more storage space than allotted to you with your new myCloud subscription, you might experience limitations with your account. You can read more about this here.