Why are SMS messages not being sent?
If SMS messages are not being delivered, the cause is usually sender configuration, failed validation, regional restrictions, or billing-related issues.
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If SMS messages are not being delivered, the cause is usually sender configuration, failed validation, regional restrictions, or billing-related issues. This article explains how to check SMS history, verify sender settings, and identify common delivery failures.
1. Check SMS sending history
Table of Contents
Start by confirming whether the message was sent successfully:
Go to Account → SMS logs
Search for the phone number or message
Review the delivery status and any error message
Common log outcomes:
Delivered
Failed
Rejected by carrier
Invalid phone number
Blocked due to formatting or regional restrictions
If the log shows no entry at all, the SMS was never triggered. In that case, verify:
Whether an automation or action listener actually ran
Whether the trigger has already fired previously and reached its limit
Whether the message was removed or disabled in the automation
2. Verify SMS sender configuration
SMS messages require a valid sender setup. Check:
The sender name or number configured for your account
That the chosen sender type is allowed in the destination country
That the sender has not expired or been removed
That your SMS provider allows alphanumeric sender names (some regions do not)
If the sender is unverified or incompatible, most carriers will reject the message.
3. Check country and region restrictions
Some countries enforce strict rules on:
Allowed sender types
Allowed characters
Sender registration
Use of alphanumeric names
Local regulations regarding marketing messages
If sending internationally, confirm that the phone number is formatted in full E.164 format.
Example format:
Incorrect formatting is a common cause of carrier rejection.
4. Check SMS Spam Protection & Delivery Restrictions
If your SMS is not being sent, it may be blocked by Hubhus’ built-in spam protection rules. These rules prevent over-messaging the same lead or phone number.
You can check and adjust these settings in:
Campaign Settings → SMS template → Spam protection
Key settings to review:
Sending to the same lead
Limit number of SMS within a specific period (e.g., max. 1 SMS every 24 hours).
If this limit is reached, additional SMS messages will be blocked.
Sending to the same phone number
Applies when the lead is the actual recipient.
If frequency limits are set too strictly, messages may not be delivered.
Blacklist & Whitelist campaigns
If a lead belongs to a blacklisted campaign, the SMS will not be sent.
Whitelisting ensures the SMS is allowed even if general restrictions exist.
If unsubscribed
Determines what happens if the lead has opted out of SMS communication.
The safest setting is Block sending to lead's number.
Activate SMS requirements
If set to conditional, your SMS may be blocked if conditions are not met.
Confirm SMS spending limits and billing status
SMS delivery can be blocked if you have reached your monthly spending limit. Check your SMS settings to verify there are no billing restrictions preventing delivery. Read more here: Configuring SMS settings
Go to Account → SMS settings and review:
- Current month's SMS bill compared to your notification threshold
- Whether a maximum monthly SMS bill limit is set
- If the current spending has reached the configured maximum limit
If a maximum monthly limit is configured and reached, the system will block sending more text messages until the count resets at the start of the next month. You can either:
- Wait until the next month when the counter resets
- Edit the maximum monthly SMS bill limit to allow additional sending
- Review whether the spending is expected or indicates an issue with automation
Summary
If SMS messages are not being delivered:
- Check SMS logs for error messages
- Verify sender configuration
- Ensure the number format and region allow the message
- Check SMS settings for spending limits and billing restrictions
Once the underlying issue is resolved, retry the automation or send a manual SMS to confirm delivery.
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