This article provides a comprehensive guide to understanding and resolving common SMS delivery errors in HighLevel. By identifying typical failure points and offering practical solutions, you can enhance your messaging success rate and ensure effective communication with your contacts.
TABLE OF CONTENTS
- What Are Common Unsuccessful SMS Errors?
- Key Benefits of Understanding SMS Errors
- How To Identify and Interpret Common SMS Errors
- Common Error Codes and What They Mean
- 1. Error 11751 – Media Message Size Limit Exceeded
- 2. Error 21610 – User Opted Out
- 3. Error 21612 – Unreachable 'To' Number from Current Sender
- 4. Error 30002 – Account Suspended Before Delivery
- 5. Error 30003 – Unavailable or Inactive Number
- 6. Error 30004 – Message Blocked by Carrier
- 7. Error 30005 – Unknown Destination Handset
- 8. Error 30006 – Landline or Unsupported Number
- 9. Error 30007 – Carrier Filtering (Spam or Policy Violation)
- 10. Error 30034 – US A2P 10DLC: Message from an Unregistered Number
- 11. Error 30008 – Unknown Error
- Additional Troubleshooting Tips
- Frequently Asked Questions
- Related Articles
What Are Common Unsuccessful SMS Errors?
SMS delivery errors occur when a message cannot be delivered to the intended recipient due to issues like invalid numbers, carrier filtering, user opt-outs, or technical restrictions. Understanding these errors helps businesses maintain high message deliverability and comply with industry regulations.
Most of these errors originate from carriers, Twilio or LC Messaging and are represented by specific error codes. Identifying and interpreting these codes enables users to take corrective action quickly and confidently.
Key Benefits of Understanding SMS Errors
Recognizing and addressing SMS errors promptly can significantly improve your communication strategy.
- Enhanced Deliverability: By identifying common errors, you can take proactive steps to prevent message failures.
- Efficient Troubleshooting: Understanding error codes allows for quicker resolution of issues.
- Improved Compliance: Awareness of carrier and platform restrictions helps maintain compliance and avoid penalties.
- Optimized Messaging Strategies: Insights into errors can inform better messaging practices and content.
How To Identify and Interpret Common SMS Errors
Accurate diagnosis of SMS errors requires checking delivery logs, identifying the error code, and using the information to adjust your messaging or recipient data.
Step 1: Go to the Conversation Logs
- Click on the Conversations tab from your HighLevel account.
- Search for the SMS log that was unsuccessful.
- Click on the unsuccessful Conversation.
- Hover over the Red Triangle Error Box.
Step 2: Locate and Identify the SMS Error Code
- The dialogue box will display the Numerical Error code and a short description of the error for that conversation (e.g., Error 30034, Error 21610).
Common Error Codes and What They Mean
The following are the most frequently encountered SMS errors within HighLevel:
1. Error 11751 – Media Message Size Limit Exceeded
Description: The total size of the media message exceeds the maximum limit allowed by the messaging provider.
Resolution:
- Compress or resize the media file.
- Ensure the file stays within Twilio’s supported MMS size limits.
2. Error 21610 – User Opted Out
Description: The recipient has opted out of receiving messages by replying with STOP.
Resolution:
- Do not message this number again unless the user sends START to opt back in.
- Ensure proper opt-in mechanisms are in place.
3. Error 21612 – Unreachable 'To' Number from Current Sender
Description: The recipient number can’t be reached using the current ‘From’ number (e.g., due to carrier restrictions or unsupported international routes).
Resolution:
- Use a local or internationally enabled number.
- Confirm routing compatibility between ‘To’ and ‘From’ numbers.
4. Error 30002 – Account Suspended Before Delivery
Description: Your Twilio account was suspended between the time of message send and delivery.
Resolution:
- Contact Twilio Support to resolve account status.
- Ensure your account remains active for message queues.
5. Error 30003 – Unavailable or Inactive Number
Description: The recipient's phone is turned off, out of range, or temporarily unavailable.
Resolution:
- Retry the message later.
- Verify the number is active.
6. Error 30004 – Message Blocked by Carrier
Description: The destination number is blocked from receiving this message.
Resolution:
- Confirm the number is valid and not carrier-blocked.
- Avoid messaging numbers with prior failed delivery history.
7. Error 30005 – Unknown Destination Handset
Description: The destination device is unreachable (e.g., turned off or out of range for extended period).
Resolution:
- Retry after some time.
- Clean your list to remove unreachable or inactive numbers.
8. Error 30006 – Landline or Unsupported Number
Description: The number cannot receive SMS—usually because it’s a landline or incompatible with SMS.
Resolution:
- Remove landlines from your list using number validation tools.
- Confirm numbers support SMS before messaging.
9. Error 30007 – Carrier Filtering (Spam or Policy Violation)
Description: The message was blocked by the carrier for violating content policies or appearing as spam.
Resolution:
- Avoid spam-like content and shortened URLs.
- Use personalized, compliant messaging.
- Register your number with A2P 10DLC or Toll-Free verification.
10. Error 30034 – US A2P 10DLC: Message from an Unregistered Number
Description: You attempted to send a message to a U.S. number from a 10DLC number that is not associated with a registered A2P campaign.
Resolution:
- Register your number through Twilio's Trust Hub.
- Link the number to an approved Messaging Service.
- Confirm proper campaign association.
11. Error 30008 – Unknown Error
Description: An unspecified error occurred during message delivery.
Resolution:
- Check the message body for formatting or content issues.
- Test with a different number or content structure.
12. Error 11200 – HTTP retrieval failure
Description: This error often occurs when images fail to load or send in conversations.
Resolution:
- Check the domain’s DNS configuration using MXToolbox. If the DNS records aren’t found or not pointing to brand.ludicrous.cloud, this can cause the image retrieval to fail.
To resolve this:
Ensure a CNAME record is set up correctly, pointing your branded domain to:
brand.ludicrous.cloud
If this is missing or misconfigured, images will appear broken in conversations. Check out Branding System-Generated Links (API Domain)
Note: To explore additional error codes beyond those most commonly encountered in HighLevel, you can view:
Full Catalog of Error Codes.
Additional Troubleshooting Tips
Understanding the technical side is helpful, but these best practices can proactively reduce errors:
- Use Verified Sending Numbers
- A2P 10DLC and Toll-Free numbers go through a vetting process that improves delivery rates and reduces filtering.
- Format SMS Content Properly
- Avoid all caps, spammy phrases, or including long URLs without a proper link shortener.
- Use a conversational tone to avoid content blocks.
- Maintain Clean Lists
- Ensure numbers are valid, formatted correctly, and that users have opted in.
- Monitor Error Trends
- Use HighLevel’s reporting tools to spot patterns in delivery issues and make proactive adjustments.
Frequently Asked Questions
Q: How can I get a user to resubscribe after opting out?
The user must send a message with the word START to the same number they unsubscribed from.
Q: Can I resend messages that failed due to a 30007 error?
Yes, but first revise the content to comply with carrier filtering guidelines before retrying.
Q: Why do some messages fail even if the number is valid?
Carriers may still block messages due to content filtering or recipient settings.
Q: How can I tell if a number is a landline?
Use number validation tools or scrub lists before uploading to HighLevel.
Q: Will HighLevel alert me of frequent SMS errors?
You can review delivery reports, but setting up notifications via workflows is recommended for real-time alerts.
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