The destination handset you are trying to reach is switched off or otherwise unavailable.
In some cases, a delivery error may occur once due to a transient issue downstream of Twilio. To test whether the issue occurs again, please attempt to send another message to the user via a REST API request.
If you see similar results, continue troubleshooting with the following checklist:
If you can rule out all of the above issues, continue troubleshooting below.
Repeated Error 30003 results on undelivered messages sent from short codes could occur if the destination user has a wireless plan that does not support short code or "Premium" messages.
Sprint customers may be able to allow messages sent from your short code by texting the phrase Allow XXXXX
to 9999, replacing XXXXX
with your short code. However, customers from other wireless carriers will likely need to reach out to their carrier's support group to enable "Premium" or short code messaging.
Repeated Error 30003 results on undelivered messages sent from long codes (regular phone numbers) and Toll-Free numbers could be due to carrier filtering.
The rules for carrier filtering vary throughout the industry, making it difficult at times to pin down exactly why a message is being filtered out. For more details including potential workarounds, please see this Help Center article "How Does Carrier Filtering Work?"
Twilio's Support team can help investigate what went wrong with delivering your message. Please collect 3 or more message SIDs in your SMS logs from the last 24 hours that were flagged with Error 30003, and open a support request.