Square-Enix's account system has notified players that "the free trial period for the following service will soon end. Please note that after the end date, you will be billed service fees for your automatically continuous options."
No player will get charged against their will as the company is suspending all accounts on the 5th so that everyone can have a choice whether to subscribe or not. Until the launch of Final Fantasy XIV's 2.0 patch, the game will be available for a discounted rate of $9.99 a month, assuming that you're sticking with just one character (additional characters are $3 apiece). After 2.0, the subscription cost will increase to the standard rate $12.99/month.