SMS Delivery Failure
Introduction
When you launch a marketing campaign or send an SMS, it is easy to take for granted that your text messages are delivered on time. But there can be numerous reasons why a message sent is not a message delivered. This article explains why your SMS is not delivered to the end-users and also gets to know the leading causes of why this happens.
Audience
This document is for the customers who are:
- Launching the SMS Campaign for the first time
- Looking out for reasons for SMS delivery failure
Below is the list of reasons why SMS may not be delivered to the end-user:
- SMS Delivery Status
- Incorrect Sender ID
- Content Restrictions
- Time restriction on Promotional SMS
- Country Code not entered
- Incorrect Country Code
- Other reasons for SMS Campaign failure
SMS Delivery Status
Table 1-1 displays the SMS delivery status, status code, label, and their descriptions:
| Status | Status Code | Label | Description |
|---|---|---|---|
| Delivered | DELIVERED | Delivered | SMS successfully delivered. |
| Failed | MOB-NOTALLOWED | Number not allowed | With the default Sender ID (KLRHXA), you can only send messages to your team. |
| Failed | NUM-LIMIT | Message-cap overrun | Message-cap overrun. |
| Not Sent | NO-CREDITS | Insufficient Credits | Insufficient credits. |
| Not Sent | SERIES-BLOCK | Series Blocked | Mobile number series blocked. |
| Not Sent | INV-NUMBER | Invalid Number | Invalid number. |
| Not Sent | SERVER-ERR | Server Error | Server error. |
| Not Sent | SPAM | Anti-Spam Rejection | Spam SMS. |
| Not Sent | BLACKLIST | Blacklist | Blacklisted number. |
| Not Sent | TEMPLATE-NOT-FOUND | Template Missing | Template not mapped. |
| Not Sent | INV-TEMPLATE-MATCH | Invalid Template | Template not matching approved text. |
| Not Sent | SENDER-ID-NOT-FOUND | Sender ID Not Found | Sender ID not found. |
| Not Sent | NOT-OPTIN | Unsubscribed | Not subscribed for opt-in group. |
| Not Sent | OUTPUT-REJ | Rejected | Unsubscribed from the group. |
| Not Sent | SUBMIT-FAIL | Submission Failed | Submission to operator failed |
| Not Sent | NOTALLOWED | Country Not Enabled. | Country not enabled. |
| Not Sent | MAX-LIMIT | Exceeded char limit | The message could not be delivered as it exceeded the maximum character limit. |
| Not Sent | CON-DND | Marked as DND | This Contact is marked as DND. |
| Not Sent | INF-CREDIT | Insufficient credits | Insufficient credits. |
| Queued | QUEUED | SMS is queued | SMS is queued. |
| Sent | NO-DLR-OPTR | Awaiting Report from Operator | In case the operator has not acknowledged the status report of the SMS. |
| Sent | SENT | Waiting for DLR | Waiting for DLR. |
| Not sent | REJECTED-MULTIPART | Multipart Rejection | Validation fail [SMS over 160 characters]. |
| Not sent | DNDNUMB | Do not Disturb | DND registered number. |
| Not sent | TIME-OUT-PROM | Off Promotional Hours | Time out for promotional SMS. |
| Not Sent | SNDRID-NOT-ALLOTED | Sender ID Not Allocated | Sender ID not allocated. |
| Undelivered | INVALID-SUB | Invalid Submission | The number does not exist. / Failed to locate the number in the HLR database. |
| Undelivered | ABSENT-SUB | Absent Subscriber | Telecom services do not provide service for a particular number. / Mobile Subscriber not reachable. |
| Undelivered | HANDSET-ERR | Handset Error | Problem with Handset or handset failed to get the complete message. / Handset does not support the incoming messages. |
| Undelivered | BARRED | Barred | End user has enabled message barring system. / Subscriber only accepts messages from Closed User Group [CUG]. |
| Undelivered | NET-ERR | Network Error | Subscriber’s operator not supported. / Gateway mobile switching error. |
| Undelivered | MEMEXEC | Handset Memory Error | Handset memory full. |
| Undelivered | FAILED | Failed | SMS expired due to roaming limitations. / Failed to process the message at the operator level. |
| Undelivered | MOB-OFF | Switched off | Mobile handset in switched-off mode. |
| Undelivered | HANDSET-BUSY | Handset Busy | Subscriber is in busy condition. |
| Undelivered | SERIES-BLK | Series Blocked | Series blocked by the operator. |
| Undelivered | EXPIRED | Expired | SMS expired after multiple re-try. |
| Undelivered | REJECTED | Blacklisted by Operator | SMS Rejected as the number is blacklisted by the operator. |
| Undelivered | UNDELIV | Undelivered | Failed due to network errors. |
| Undelivered | TL-NT-MTCHD | Template Mismatch | The template does not match the template registered on the DLT platform. |
| Undelivered | SDR-TL-MSMAT | Sender ID Template Mismatch | The sender ID used along with the template ID do not match as per the registration in DLT portal. |
| Undelivered | TL-NT-FOUND | Template Not Found | The message content sent was not found in the DLT platform as a registered template. |
| Undelivered | TL-LMT-EXCED | Template Limit Exceeded | The variable content sent exceeds the allowed limit. |
| Undelivered | TL-BLKLST | Template Blacklisted | The message template pushed has been blacklisted at the DLT platform level. |
| Undelivered | TL-INACTIVE | Template Inactive | The message template sent is in inactive status at the DLT platform level. |
| Undelivered | SNDR-NT-MTCH | Sender Not Registered | The sender ID used is not registered in the DLT platform level. |
| Not Sent | KL-TEMPLATE-ID-NOT-FOUND | Template ID Missing | SMS not sent as matching template ID not found for content. |
| Undelivered | REJECTD | Rejected | SMS Rejected as the number is blacklisted by the operator. |
| Not Sent | BLACKLIST | Blacklisted in the application | The mobile number to which you want to send is blacklisted. |
| Not Sent | INV-MOB-PATTRN | Invalid mobile number | The recipient mobile number is invalid. |
| Undelivered | INV-ENTIY-ID | Invalid Entity ID | The Entity ID that customer used is Invalid. |
| Undelivered | PRFT-NT-MTCH | Preference Not Match | This error code is received for Service Explicit content only. When the end-user is registered under DND. This is completely based on the DND preference selected by the end-user. |
| Undelivered | SNDR-NT-REG | Sender Not Registered | Sender ID is not registered in the DLT Platform. |
| Not Sent | KLR-INV-NUMBER | Invalid mobile number | The recipient mobile number is invalid. |
| Undelivered | TL-ID-INVLD | Template ID Invalid | The template ID that customer using is Invalid. |
| Undelivered | SNDR-NT-REGD | Sender Not Registered | Sender ID is not registered in the DLT Platform. |
| Not Sent | URL-NT-SENT | URL is invalid | SMS not sent as replaceable URL details not sent in API. |
| Not Sent | URL-SHRT-FAILED | URL shortening failed | SMS not sent as URL shortening failed. Please contact support at [email protected]. |
Incorrect Sender ID
A Sender ID is a set of alphanumeric characters that represent the identity of the sender. It is the name that appears in the From field when you send an SMS campaign. Also, an incorrect From field can be one of the reasons for SMS campaign failure.
By default, Kaleyra.io will create a Sender ID during the signup. However, using this default ID, you can only send SMS messages to your mobile number and the numbers that are added to the Team. Hence, you must create your own Sender ID to launch a global SMS campaign or send an SMS to other mobile numbers.
NOTE
A-Team is a group created during your signup, allowing you to invite members and join your Team in the Kaleyra.io.
The rules for creating a Sender ID may vary from county to county. For example, In India, you need to register the Sender ID with the network operator on the Distributed Ledger Technology (DLT) platform. Once registered, only then you can apply it in Kaleyra.io. It is recommended to go through the global registration process before you create a Sender ID.
For more information on the Global Registration Process, see Global Registration Process
For more information on Creating a Sender ID in Kaleyra.io, see Creating a Sender ID. To view the API Key and the SID, see View API Key and SID.
Content Restrictions
Many countries enforce different types of content restrictions on network operators.
For example, in India, companies must register their Content and Consent Templates on the DLT. Japan does not allow you to add URLs in the message body.
For India specific information on the Content Registration process, see Content Registration
NOTE
Before you start an SMS campaign, we recommend you to research the content requirements of each destination country.
Time restriction on promotional SMS
SMS campaigns are one of the best ways to promote your products. However, there are time restrictions enforced by various countries.
For example, in India, if you run a campaign outside the permitted hours of 9:00 PM to 9:00 AM then, the SMS campaign shows as failed or message undelivered.
NOTE
Before you start an SMS campaign, we recommend you to research the time restrictions for each destination country.
Country Code not entered
Before sending an SMS to the contacts, ensure to prefix the country code to the mobile number. Else, the system will consider the first two digits of the mobile number as the country code, which results in the SMS campaign failure.
Incorrect Country Code
Ensure the country code entered is correct when you are sending SMS to multiple countries.
Other reasons for SMS Campaign Failure
Below are some of the other reasons:
- Exception Time Out
- Message Inbox memory is full on your mobile device (Lack of space in the receiver's Mobile internal memory for new messages).
- The number is out of reach (not reachable or out of coverage area).
- Handset failure(The receiver handset is damaged or is not working properly).
- Network failure (The carrier network is facing some technical difficulties and messages are just not able to be delivered. (Downtime caused by network problems, Security failure, Hardware failure, etc.).
NOTE
Kalyera's system is configured to retry the delivery of messages within a few hours. If the message still fails, it is marked as Failed.
If you are still not able to resolve the issue, contact our support team at [email protected].
Updated about 1 year ago