If an automated SMS message you set up isn’t going out as expected, there are a few things to check. Start with your system settings, then move on to guest preferences and external delivery issues.

1. SMS sending isn't enabled

Unlike emails, SMS messages aren’t enabled by default. The feature must be turned on manually, because each SMS has a cost.

To enable SMS sending:

• Go to Webtools > Booking engines > General options and enable Send SMS by default.

2. The guest didn’t opt in or was opted out

Even if Send SMS by default is enabled, messages won’t be sent unless the guest has opted in.

Here’s how opt-in works:

• At the time of booking: If the guest turns off the SMS confirmation switch, no confirmation message will be sent.
• After booking: The guest’s opt-in status can be edited by your team by in the Guest details section of booking. Check there to make sure they’re still opted in.

3. The phone number is invalid

Sirvoy will try to send messages if the number appears valid, but there's no way to fully verify whether the number works. If the number is incorrect, the message may fail, and the carrier may still charge your account.

Make sure the number includes the country code and follows the standard international format.

4. The message was blocked by the carrier

Some mobile carriers automatically filter SMS messages that contain:

• Email addresses
• Website links
• Spam-like wording

This is especially common in the U.S. To improve delivery rates, keep messages short and avoid using links or email addresses when possible.

5. The recipient’s country is restricted

SMS delivery is not supported in every country. In some cases, delivery is limited or blocked entirely due to local carrier rules or restrictions.

See the full list here: SMS restrictions by country.