SMS charges: Google does not charge for using this service. However, mobile providers' standard charges will apply to any SMS messages sent from a mobile device to Google Chat. Please check your mobile provider's price plan for details.
The feature is very simple and straightforward: you can now choose to send an SMS to your friend instead of a regular text message if you already have a phone number added to this person’s contact information in your Google account or you can send a text message to a new phone number.
Google has also reserved thousands of phone numbers in 406 area so once you send a text message from Google Talk, one of such numbers is associated with your Google account and all the messages you send will show as sent from this number. The phone number works both ways so if the person you send a text message to replies to the phone number associated with your Google account, you will get the reply as a chat message as well.
If you send the command 'STOP,' you'll block all SMS messages from Gmail accounts.
To prevent abuse, any Gmail user who sends an excessive number of SMS messages from Gmail, without getting any responses in return, will be blocked from sending further SMS messages.
Gmail users can send SMS messages to their contacts through Gmail Chat. To write back, reply to the message as you would any other text message, and your message appears as a Chat message in your friend's Gmail account.
Anyone with a Gmail account can send SMS messages to their contacts in certain countries through Gmail Chat. To start texting, turn on the Text Messaging (SMS) in Chat labs feature in the Labs tab of your Gmail account settings. Once the lab is enabled, you can send text messages to your friends' phones.
If you don't have a Gmail account, you can create an account at http://mail.google.com/mail/signup.
Below is a list of supported mobile operators for SMS Chat in Gmail
If you are a mobile operator, and wish to integrate with the SMS feature of Gmail, please drop us a note to: mobile-operators-gm...@google.com