Your paid subscription can be cancelled via 'Profile settings' - 'Billing' tab at any time. See the sections below for more information.
Note that once the subscription has been cancelled, your account will become free immediately.
Cancelling your subscription in Saimaa (2020) interface
Click your profile picture in the top-right corner, then click 'Profile Settings' and select the 'Billing' tab. Next, click the 'Cancel' link next to the name of your plan, select the reason for cancelling your subscription and click the blue 'Cancel subscription button':
Cancelling your subscription in Ruovesi (2017) interface
Click your profile picture in the top-right corner, then click 'Account Settings' and select the 'Billing' tab on the left. There, click the grey button that reads ‘Cancel Subscription.’