Why are my SMS messages not being sent?
If SMS messages aren't delivering, the cause is almost always one of four areas: the automation didn't fire, spam protection blocked the message, there's a sender or number issue, or the account has reached its monthly SMS limit.
TL;DR
Check the lead’s Activity tab first — did an SMS attempt appear? If not, the trigger never fired. If it shows "failed", check the phone number format (+45XXXXXXXX), sender configuration, and spam protection rules. Check Account → Communication → SMS settings for monthly spending limits.
4 things to check
Did the SMS trigger at all?
Open the lead → Activity tab. If there is no SMS entry for that lead, the automation or action listener never fired. Check: "Max fires per order" reached? Automation conditions match? Message disabled?
Spam protection blocked the message
Go to Campaign settings → SMS → Spam protection. Check: frequency limit (max SMS per lead per hour/day), blacklist/whitelist rules, unsubscribe settings, and conditional send requirements. Any of these can silently suppress sending.
Phone number or sender issue
Phone numbers must be in full E.164 format: +4512345678. Missing country prefix is a common cause of carrier rejection. Also check that your sender name/number is valid and allowed in the destination country (some regions don't allow alphanumeric senders).
Monthly spending limit reached
Go to Account → Communication → SMS settings. If you've configured a maximum monthly SMS limit and it's been reached, all SMS will be blocked until the counter resets at the start of the next month. Increase the limit or wait for the reset.
Read more⌄
SMS delivery status codes (on the lead)
- Delivered: carrier confirmed receipt — message reached the handset.
- Failed: carrier rejected the message — check number format and sender configuration.
- Rejected by carrier: often a regional restriction or invalid sender type.
- Invalid phone number: number doesn't match expected format or country prefix is missing.
- Blocked: Hubhus spam protection stopped the send before dispatch.
Quick checklist
- Lead Activity tab — does an SMS entry exist? What status?
- Automation — is "Max fires" reached?
- Template — conditional send requirement evaluated to true?
- Template spam settings — frequency/blacklist/unsubscribe blocking?
- Lead — phone number in E.164 format?
- Account → Communication → SMS settings — monthly limit not exceeded?
- Account → Communication → SMS settings — sender name valid for destination country?
Common searches
SMS not sent • SMS failed • SMS not delivered • SMS spending limit • phone number format SMS • SMS spam blocked
Was this article helpful?
That’s Great!
Thank you for your feedback
Sorry! We couldn't be helpful
Thank you for your feedback
Feedback sent
We appreciate your effort and will try to fix the article