No. There are no setup or hidden fees. However, you will be charged for additional credits used beyond your current plan.  For example, if you are subscribed to 100 credits per month and are about to send your 101st message within a 30-day period, then you'll be charged an additional $0.07 (7 cents) per message, which is collected at your next billing period. Overages for credits range from $0.07 - $0.03 depending on the plan you are subscribed to. In some cases, it is more affordable to simply go over a few credits rather than upgrading your account. In other cases, it may make more sense to upgrade. You can upgrade and downgrade your account at any time.