Sometimes, messages sent through Notify may fail to reach a contact by SMS. When this happens, we display failure codes in the Notify CSV report to help you understand what went wrong. This article explains how to interpret those details and what steps you can take.
How to locate the Delivery Failure codes in Notify?
Navigate to the Notify tab.
Click the Notify message to view the delivery results
Click on Download as CSV
Open the CSV file in a spreadsheet application such as Microsoft Excel, Google Sheets, or Apple Numbers.
Once the file is open, you can view the Status column to identify contacts with a Failed status. You can also search for a specific contact by using CMD + F on Mac or CTRL + F on Windows.
To view the reason for a failure, scroll to the right to find the Twilio Code and Bandwidth Code columns. These codes indicate the reason the contact failed.
Delivery Failures: Understanding Failure Codes
When an SMS fails to deliver, the error code from the carrier is the key to understanding the problem.
Below is a list of some common error codes and what they typically mean:
| Error Code | Reason | Description |
SS-01 | Invalid Phone Number | The phone number is blank or does not contain the required 10 digits for a standard phone number. |
20 | Network Error | The carrier delivering the text message had network issues. This is a temporary error. |
30 | Spam Detected | SMS delivery failures often occur due to carrier-level spam filters, which block messages based on hidden and constantly changing rules. |
40 | Invalid Source Number | The source number is either incorrectly formatted or not SMS-enabled. |
50 | Invalid Destination Number | The destination number is either entered incorrectly, not SMS-enabled, or is a PSTN landline. |
70 | Destination Permanently Unavailable | The phone number you’re trying to reach appears to be inactive, and the carrier hasn’t shared a specific reason. Double-check that the number is correct. If possible, try reaching the user at a different number to make sure your messages are sending properly. |
80 | Destination Temporarily Unavailable | The destination (“dst”) phone number can’t be reached. This usually means the phone is turned off or out of coverage. Try resending the message later. |
90 | No Route Available | The carrier and fallback carriers were not able to deliver the SMS message because no route was available. Carriers don’t provide a reason why a route is unavailable, but this is typically a carrier issue. |
100 | Prohibited by Carrier | The carrier rejected the message because the network doesn’t support the message being sent. This can occur if the destination network doesn’t support SMS. |
200 | Source Number Blocked by STOP from Destination Number | The destination has opted out of the campaign and blocked all messages from the sending phone number. All messages to destinations that have opted out are blocked until the destination opts in with another response. |
30003 | Message Delivery - Unreachable destination handset | The message failed due to an unavailable or unreachable destination. Common examples are a user who is outside of cellular service or whose mobile device is powered off. |
30005 | Message Delivery - Unknown destination handset | The delivery of your message failed due to an unknown or inactive destination number, for example a number that is no longer in service. |
30006 | Message Delivery - Landline or unreachable carrier | The message delivery failed due to the destination being a landline and incapable of receiving SMS, or an unreachable destination carrier. |
| 30034 | Unregistered Number | There is an issue with your communication registration. If you see this error, please contact our Support team. |
"nil" or "null" | The delivery status is unknown or undefined | The service that sends your text messages didn’t get confirmation from the mobile carrier that the message was delivered. This can be treated as a "no-receipt, no-acknowledgment" status and is different from a specific failure code, like "invalid number" or "phone busy." |
⚠️ If you see an error code not listed here, please reach out to our support team at help@schoolstatus.com