Gmail Help

A quota is an allocation of SMS (text messages) that you're able to send to a mobile phone:

1. Initially, you're granted a quota of fifty messages.
2. Every time you send a message, your quota decreases by one.
3. Every time you receive an SMS message in Chat (for example when a phone user replies to one of your messages) your quota increases by five, up to a maximum of 50.
4. Messages sent or received to/from phones in North America don't have a quota.

If your quota goes down to zero at any point, it will increase back up to one 24 hours later. So, you won't ever be locked out of the system.

"Buying" additional messages

Keep in mind that if you'd like a higher message quota, you can always send an SMS to your own phone, and then reply to that message multiple times. Every time you send a reply message, your quota is increased by five. Effectively, you're buying more messages by paying your phone company for these outgoing messages.