The payment will be charged to your iTunes account at confirmation of purchase and the subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Your account will be charged for renewal within 24-hours prior to the end of the current period, at the subscription price option you have previously selected.

You can manage the Realms subscription and turn off auto-renewal by accessing your iTunes Account settings after purchase. There is also a button in-game that take you to these settings. If you cancel after your subscription has activated, you won’t be refunded for the remaining active period of the subscription. Any unused portion of a free trial period will be forfeited when the user purchases a subscription.