URL : http://www.emailcontact.com/kb/question.php?ID=44
You can cancel your Email Contact service at any time. However, the service plans are prepaid and if you cancel your account it will stay active until the end of your current billing cycle. If you purchased the monthly service on the 15th of the month, then your billing cycle would continue from the 15th of the month to the 15th of the next month. If you were to cancel your account on the 20th day of the month, your account would still stay active until the last day of your billing cycle. If you pay monthly or yearly, and schedule your account for cancellation in the middle of the billing cycle, your account will stay open until the end of the monthly or yearly billing cycle.
For instructions on canceling your account, click here.