Currently, Airbnb Connect service can only automatically send PIN codes to Airbnb guests via email.

We understand that many guests wish to receive PIN code via SMS as they may not have connection to the internet while travelling and will not be able to receive their PIN codes. While we are unable to support this feature for now, we are considering it as a feature to include in the future. 

If you wish to send a PIN code to a guest via SMS, you may wish to do so manually, or send them the PIN code email earlier.

We are unable to send PIN codes via Airbnb message service, as we do not have access to this feature.