Klaviyo experienced a major incident on August 27, 2026 affecting Email Sending and Processing and 1 more component, lasting 3h 33m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Aug 27, 2026, 12:09 AM UTC
At 3:25 PM US/Eastern on August 26, 2026, we began experiencing an issue affecting where profiles are not progressing past a time delay action in flows as expected. This is affecting flow sending across all messaging channels, including email, text messaging, push, and WhatsApp. Message sending from campaigns and flows that do not include time delay actions are not impacted. We are actively working on a fix. We will share another update as soon as we have more information.
- identified Aug 27, 2026, 01:15 AM UTC
Our Engineering team has identified the cause of this issue and is working to implement a fix to resolve the remaining impact on sending for flows affected by the time delay issue. Once the fix is rolled out, we will review and repair any impacted flows. We are working to resolve this as quickly as possible and will share another update shortly.
- monitoring Aug 27, 2026, 01:51 AM UTC
As of 9:30PM US/Eastern, flows have resumed sending as expected across all affected messaging channels. We are processing the backlog of affected flow messages. A fix has been deployed and system performance is improving. We continue to monitor closely and appreciate your patience throughout this incident.
- resolved Aug 27, 2026, 03:42 AM UTC
As of 11:26 PM US/Eastern on August 26, 2026, the repair to process affected flow messages from the window of impact has been completed, and flow sending has resumed as expected across all channels. We apologize for the disruption this caused. This incident has been resolved.