When your SMS campaign is not working, you might assume the issue lies with your copy, contact segmentation strategy, or timing. But the one important question that most people forget to ask themselves is, “Did my SMS even reach the recipient?” In the SMS marketing world, getting your message delivered is as important as what it says, yet most businesses focus only on other factors and miss the most important one – SMS delivery . An undelivered message can ruin your SMS campaign metrics; it can also cost you customers and affect your ROI.

Don’t worry, the “SMS campaign not working” and “message not delivered” are often easy to fix. In this blog, we will break down the common reasons why SMS fails and ways to fix it.

Key Takeaways

  • SMS campaigns do not work because of various issues like copy, timing, segmentation, or delivery issues.
  • To fix it, write clear, value-driven SMS copy with a proper CTA and send SMS at the right time.
  • Segment customers properly and send relevant messages.
  • Use a phone number validation tool like Landline Remover and filter numbers that can’t receive SMS, like landlines, VoIP, and known litigators.
  • Use an opt-in and opt-out strategy and optimize content to avoid spam filters and maintain SMS compliance.
  • Monitor metrics like delivery rate and opt-out rate to track SMS campaign performance.
  • A/B test performance and constantly refine your SMS strategy.

What is SMS Delivery and its Different Statuses?

SMS delivery means the number of messages delivered to their intended recipients out of the total number of messages you send out. Importantly, a message sent does not mean a message delivered. It’s possible that an SMS sent from your SMS marketing platform never reaches your user’s phone because of various delivery issues.

Here are different SMS delivery statuses you must be aware of:

Sent – Your SMS was accepted by the Short Message Service Center but never reached the recipient’s device.

Delivered – Your message successfully reached the recipient’s phone.

Failed – The SMS couldn’t be delivered due to issues like an invalid or deactivated number.

Rejected – The carrier has blocked your message before it could reach the recipient.

Expired – The carrier attempted to send your SMS, but the delivery window elapsed, and the SMS was never delivered.

Undelivered – The message didn’t reach the recipient at all, and this status falls under “Expired” or “Failed.” 

Understanding these delivery statuses allows you to easily identify what is working and what is not working in your SMS campaign, so you can fix any issues.

1. Invalid Phone Numbers

Sometimes, a simple typo error, like a wrong or missing digit, an incorrect country code, or an invalid recipient number, causes SMS campaign failure. Customers switch their carriers, deactivate old numbers, or simply change their phone numbers. In such a scenario, when you send SMS to these numbers, you waste your SMS credits, but your message never reaches the intended recipient, and it lowers your delivery rates.

To fix it, you can use a phone number validation tool like Landline Remover,  which identifies phone number line type and removes landline or invalid numbers from your contact list. This way, you can make your contact list fresh and verified. Also, encourage customers to update their data to maintain an active database.

2. Carrier Limitations

When it comes to SMS marketing, mobile carriers have strict SMS compliance rules to protect users from spam, fraudulent messages, or message overload. When you use excessive promotional language in your SMS copy, like “FREE”, “Click Now”, or “LIMITED TIME OFFER”, it can be the reason for SMS campaign failure. Even some mobile companies limit the number of recipients for bulk texting if you use a non-registered number.

If you want to fix this issue, avoid using phrases and formatting styles that flag your messages as spam. Don’t use salesy phrases and unnecessary caps and punctuation. Also, only send a message to those users who’ve given you explicit permission to send messages. Use a 10DLC-registered number, as it increases your business’s credibility and helps customers perceive you as a legitimate business.

3. S.H.A.F.T Content in Text Message

Just like spammy words, certain types of content can also be the reason your SMS campaign is not working. Avoid sending harmful, illegal, deceptive, or offensive content, as these are prohibited in SMS campaigns. These prohibited topics include:

  • Adult content
  • Drug, alcohol, gambling, or tobacco
  • Offensive or discriminatory language
  • Phishing or questionable financial offers

To resolve this issue, you should proofread your content and ensure it does not include S.H.A.F.T. (Sex, Hate, Alcohol, Firearms, and Tobacco) related content. Also, make sure that your messages don’t sound robotic or unnatural. Stick to SMS compliance rules and guidelines set by your SMS marketing platform and carrier.

4. Suspicious Links

When you include a link in a text message, mobile carriers become cautious because links are often used in scams. As a result, your SMS service provider flags and blocks suspicious URLs, and your message never reaches the recipient. So, if you’re not seeing the expected response or are receiving many “message not delivered” errors, a suspicious link could be the reason. 

To resolve this issue, use a trusted link shortener service that integrates easily with your SMS marketing platform . Avoid including multiple links in a single text message. Use the verified domain linked to your brand, and ensure that your brand name is clearly mentioned in each text message.

5. Message Bombarding

When you send excessive messages, it can irritate your customers, cause network overload, and increase the chances of your message being considered spam by the carrier. Ultimately, this can cause text message failures.

To avoid this issue, you should schedule your message in batches to send it to a specific segment of customers. You can also segment your audience into smaller segments based on customer behavior, location, and more to send personalized text messages.

6. Blocked Number

It is essential that your mobile carrier sees you as the trusted sender. If your number is not verified by a mobile carrier or your sender details match the blacklist number, your SMS campaign will fail.

You should use a 10DLC registered number to resolve this issue. Also, follow the network and regional requirements for the sender data authentication.

7. Wrong Message Type

Usually, P2P (Person-to-Person) routes are used for individual communication, while A2P (Application-to-Person) routes are designed for bulk texting. If you use your personal number to send bulk messages, you may create a P2P vs A2P conflict, causing your SMS campaign to fail.

In such a case, you should use a registered SMS service for the appropriate routing of your message. If you want to send bulk messages, use short codes. Additionally, choose the appropriate delivery method for different message types, as MMS is restricted in some regions.

8. DND Numbers

If the person you’re trying to send a message to has listed their number on an official Do Not Disturb list, you will get an SMS failure error even if you’re sending legitimate messages.

To fix this, you should set an appropriate route for promotional and transactional messages to deliver important text messages to your customers who are on the DND list. Check your local DND regulations properly and ensure you have proper permissions before starting your SMS campaign.

9. Unicode and GSM format mismatch

Generally, the GSM format supports an SMS character limit of 160 characters while limiting some symbols and emojis. The Unicode message format allows up to 70 characters, including Arabic, Chinese, and Cyrillic scripts. If your text message exceeds the character limit, it automatically switches encoding to accommodate the text, and this can be the reason for an undelivered message or an incomplete message.

To fix this issue, keep the SMS character limit in mind when crafting your message. Avoid using unsupported or hidden characters, and ensure that the encoding aligns with your carrier and regional standards.

10. Recipients Opt-Out or Block Your Number

It’s possible that the recipient has unsubscribed from your send list or blocked your number. In such cases, your messages get automatically rejected.

If you don’t want this to happen, respect your customers’ decision and confirm opt-outs. Use a phone number filtering tool like Landline Remover to maintain the hygiene of your contact list by removing unsubscribed or inactive numbers from your list.

11. The Recipient Device is Out Of Reach

Some recipients may switch off their phones, enable airplane mode, or live in an area where signal coverage is low. Additionally, certain countries restrict roaming for foreign users, which can also cause SMS campaign failures.

To address this, try sending the message again if the first attempt fails. Use alternative channels like email, push messages, iMessage, and instant messaging apps. Maintain a message queue and keep undelivered messages in the queue for retry attempts.

12. Carrier Service Issue

Sometimes, large-scale issues occur within mobile networks, like network outages during peak times or busy seasons, technical errors, internal glitches, regional outages because of weather conditions, or infrastructural damage.

To address these challenges, you should use an omnichannel communication tool such as messengers, in-app messages, and push notifications. Set an automatic fallback option to reroute your text message in case it fails.

13. Deactivated SMS Function

Your SMS campaign might fail if the recipient has disabled SMS on their phone. Some users intentionally do it, or sometimes it happens due to a software update or a system reset.

To fix this issue, you should encourage recipients to verify their SMS settings when they subscribe to your network. Also, use alternative communication channels to reach users who are unreachable via SMS.

14. Network Congestion

Another possible reason your SMS campaign is not working could be excessive SMS traffic or message overload during holidays, evenings, or weekends, which causes network congestion.

You should optimize your sending schedule to avoid peak hours. To fix the issue, you should partner with an SMS service provider that uses multiple carrier routes for better load distribution.

15. Insufficient Balance

It’s possible that your SMS platform account is empty or you’re using a terminated mobile plan. This can be the reason why SMS fails.

To fix this, before launching any new SMS campaign or sending bulk messages, you should first check your balance. You can also set up auto top-ups so you don’t lose customers due to insufficient balance.

Achieve Exceptional SMS Delivery With Landline Remover

SMS delivery directly impacts your business ROI and customer experience. To improve it, you need the right tool, like Landline Remover, which easily integrates with your SMS marketing platform, offers reliable support, and helps you build trust and visibility. Improving SMS delivery is not a one-time fix but an ongoing effort. By keeping the above-discussed practices in mind and combining them with a robust platform, you can effectively solve your SMS marketing challenges. Moreover, you can turn your SMS campaigns into a reliable, high-impact channel for communication and customer engagement for your business.

Check the Landline Remover demo and see how businesses are making their SMS campaigns shine.