Credits are the form of currency used to measure each message you send to each contact. Typically, it costs 1 credit to send 1 SMS message but may vary upon plans for sending MMS messages.
1 credit = $0.05 cents*
1 SMS message (160 characters or less) = 1 credit
1 MMS message (up to 1600 characters and or includes an image or video) = up to 3 credits (varies between plans)
Depending on the plan you choose, MMS messages become cheaper and require less credits to send your message. Learn more about the difference between MMS and SMS.
To view how many credits your composed message will cost, click on the Review button and hover over "More Info" on the Review Message page.