SMS Event Processing Delays

Incident Report for Klaviyo

Resolved

SMS events have been restored to real time processing as of 6:38 PM ET on May 19, 2026. Our Engineering team has monitored performance and see that systems have fully recovered. This incident has been resolved.
Posted May 19, 2026 - 20:30 EDT

Identified

We have identified the cause of the issue and SMS event processing is recovering. Delays in processing SMS events are currently around 3 hours and continue to decrease. SMS campaign sending continues to be unaffected and recipients are continuing to receive messages at the expected send times. Customers may continue to see downstream delay in SMS event-triggered flow sending, real-time segments built on SMS event data, and reporting until processing has fully caught up. Customers may also encounter errors when creating and registering RCS agents, and when viewing videos within the platform. We'll provide updates as soon as more information is available.
Posted May 19, 2026 - 18:21 EDT

Investigating

SMS event processing is delayed by approximately 2–3 hours. SMS sending is not impacted and recipients are receiving messages at the expected send times. This is impacting when SMS-related events appear in customer accounts, which may cause a delay in SMS event-triggered flows, real-time segments built on SMS event data, and reporting. Our team is actively investigating and we'll provide updates as soon as more information is available.
Posted May 19, 2026 - 16:36 EDT
This incident affected: SMS Sending (SMS Sending - Toll Free Number SMS, SMS Sending - Toll Free Number MMS, SMS Sending - Short Code SMS, SMS Sending - Short Code MMS, SMS Sending - Other) and Analytics, Segmentation, Flow Triggering.