SMS and email credits
Text messages use SMS credits. Emails to guests count toward your email limit.
Included credits
Some plans include SMS credits. You can see what you have left under Usage.
Buying more
Buy SMS credit packs from Billing as a one-time purchase, on any plan where SMS sending is available. You only pay for the credits you choose.
Long messages
A long text or one with special characters can use more than one credit.