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Decoding Common SMS Issues and Deliverability Questions

March 28, 2024

Decoding Common SMS Issues and Deliverability Questions

6 min read

Texting comes with its own set of regulations, challenges, technical snafus, and queries. If you've stumbled upon an SMS error code in, don’t sweat it. We've compiled a comprehensive breakdown of common carrier errors, providing insights into resolutions. 

When you hit “send” on an SMS or MMS, the message will have a final status. The four statuses for an SMS message:

  • Delivered: The SMS message was either delivered or accepted for delivery by the network operator.
  • Failed: The SMS message was NOT delivered.
  • Sent: The SMS message was sent, but no final status is available. Delivery could be delayed, unreported, or failed.
  • Rejected: The SMS message was rejected, meaning that it was not accepted for delivery.

Common Error Codes and What They Mean: allows you to view error reports for individual broadcasts as well as errors happening for multiple organizations. To learn more about error reports, reach out to your Customer Success Manager.

The most common causes for an error code:

  • The number format is invalid
  • The device is switched off
  • The number is deactivated or unallocated
  • Signaling issues between the device and the network operator
  • A number has reached its throughput limit

Error Description
1000 Delivering your message failed for reasons that are unknown.
217217 This error occurs if there is a problem with the outbound channel's registration with The Campaign Registry.
30003 The recipient's number is unreachable. This error code often occurs if the destination phone is switched off.
30004 This error could indicate that message delivery has been blocked by upstream providers and/or the destination device.
30006 Most often, this error indicates that the text attempted delivery to a landline or non-mobile device.
30007 This error code is most often associated with carrier filtering. Carriers block messages when they receive complaints from contacts or the opt-out rate for texts sent for this organization exceeds a carrier limit.
30008/40008 This is the "grab bag" of unspecified failures. It could be from a phone being turned off, roaming, out of network, or using a very old operating system.
30022 This error occurs when a registered organization sends too many messages in a calendar day. The "daily cap" of messages (particularly to T-Mobile customers) has been exceeded.
30034 The number used to send texts is not registered with any 10DLC use case.
40001 Not routable (the destination number is a landline or a non-routable wireless number).
40016/40018 This is for a 10DLC sending limit reached (exceeded throughput limits for allocated use case).

[Learn More: Full Error Code Repository]

Things to Keep in Mind Before You Hit Send:

1. Beware of Encoding Issues: Different devices and carriers may use different character encodings or message limitations. This issue commonly arises when sending media, special characters, emojis, or scripts. Make sure your platform can compress and format messages for different carrier specifications.

[Learn More: HD MMS for seamless media compression]

2. Mind Your Scheduling and Timing: Timing plays a significant role in the effectiveness of SMS campaigns. Factors such as the target audience's demographics, time zone considerations, and the nature of the message should be taken into account when scheduling SMS campaigns. Just keep in mind that there are “quiet hours” for phone communication and customers should avoid sending messages between 9 PM and 9 AM.

3. Don’t Forget Opt-Out Mechanisms: Users should adhere to regulations regarding opt-in and opt-out options. Users may have questions about how to unsubscribe from messages or control the frequency of notifications they receive. Service providers should make these options clear and easily accessible to users.

Your Checklist for the Best Possible Delivery Rate:

1. Check Your Character Count: SMS messages typically have a character limit of 160 characters per message. When sending longer messages, you may get split into multiple segments, which can sometimes lead to confusion or fragmentation upon delivery. Users should be mindful of this limit and consider using concise language to help reduce error rates.

2. Check Your Numbers: Ensure that the phone numbers you are sending messages to are accurate and up-to-date. Using outdated or incorrect numbers can result in failed deliveries or messages sent to the wrong recipients. Regularly update your contact lists and verify numbers to improve delivery accuracy.

3. Check Your Throughput Rate: Ensure that your messaging platform or message type can handle the volume of messages you intend to send within a given timeframe. Higher throughput rates can prevent delays and ensure timely delivery.

4. Check Your Content: Relevance and quality of your message content are key factors affecting delivery rates. Avoid spammy language, excessive use of symbols, or anything that might make a user think a message is junk.

5. Check-In with Your Support: Regularly communicate with your support team or service provider to address any issues or concerns regarding message delivery. They can provide insights, troubleshoot problems, and offer assistance in optimizing your delivery strategy.

Navigating the SMS landscape isn't without its challenges, but armed with knowledge and the right tools, success is within reach. Whether you're a seasoned marketer or new to SMS campaigns, understanding common issues and best practices is key to unlocking their full potential. And if you ever find yourself stumped, our team of experts at is here to help.

And if you ever find yourself lost, our team of 10DLC pros is here to guide you through. Reach out to one of our experts at with any questions about the vetting and registration processes.

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