How to create an SMS error segment
Learn how to create a segment of SMS subscribers whose delivery errors meet specific conditions. It’s a best practice to exclude this segment from most SMS campaigns to avoid sending to profiles who may not receive them.
What is an SMS error segment?
This segment groups together profiles who can receive text message marketing and have had certain delivery errors. These errors can be temporary and do not necessarily mean the profile has an invalid phone number.
It’s a best practice to exclude the SMS error segment from most SMS campaigns so that you avoid sending to those who likely won’t receive them. This is beneficial for 2 reasons:
- Better SMS deliverability
- More efficient use of your SMS credits
Why aren’t these users unsubscribed automatically?
In many cases, the SMS errors mentioned below are temporary, so you don’t want to unsubscribe someone right away. Klaviyo does automatically remove SMS consent for some errors, including invalid mobile numbers. Learn more about when Klaviyo removes SMS consent automatically.
For profiles who still have SMS consent, exclude this segment from most campaigns, but allow flows (and SMS conversations) to send.
Create an SMS error segment
- Navigate to Audience > Lists & segments.
- Click Create > Segment.
- Name the segment (e.g., SMS errors). If you’re entering the name in a Create segment panel, click Create segment to open the builder.
- Add the following conditions. Use AND after the consent condition, then OR between the 6 error conditions. Profiles must be able to receive text message marketing and match at least 1 error condition.
- If someone can or cannot receive marketing > can receive > text message marketing
AND - What someone has done (or not done)
> Failed to Deliver Text Message at least once in the last 30 days
Where Failure Type equals Device unreachable
OR - What someone has done (or not done)
> Failed to Deliver Text Message at least once in the last 30 days
Where Failure Type equals Device disconnected
OR - What someone has done (or not done)
> Failed to Deliver Text Message is at least 2 over all time
Where Failure Type equals Device unreachable
OR - What someone has done (or not done)
> Failed to Deliver Text Message is at least 2 over all time
Where Failure Type equals Device disconnected
OR - What someone has done (or not done)
> Failed to Deliver Text Message at least once over all time
Where Failure Type equals Invalid mobile number
OR - What someone has done (or not done)
> Failed to Deliver Text Message is at least 5 over all time
Where Failure Type equals Unknown error
- If someone can or cannot receive marketing > can receive > text message marketing
- Click Create segment.
SMS error segment and list cleaning
The SMS error segment is a key part of the list cleaning process for SMS. This segment should be excluded from most campaigns on an ongoing basis. Once profiles have demonstrated a longer, sustained period with errors, you can consider removing SMS consent from the profiles.
Learn more about SMS list cleaning and the long-term error segment.
Outcome
You now have a segment of SMS subscribers who meet the error conditions above. Some conditions use errors over all time, so a profile can remain in this segment even after receiving a later message successfully.
When creating an SMS campaign, open Don't send to in the audience settings and select this segment. In the campaign wizard, click Next to save your recipient choices and continue.

Additional resources
- How to clean SMS lists
Learn about list cleaning for SMS, including why list cleaning is important, how to list clean, and when to clean your lists.
- Understanding and reviewing your SMS deliverability
Learn the important aspects of SMS deliverability, including how to evaluate it and best practices.