Major incident

Klaviyo: Flow Sending Delays

Affected: Email Sending, Text Message Sending, WhatsApp Sending, Mobile Push Sending, Flow Editor, Processing

Current status of Klaviyo: Operational — live Klaviyo status

Timeline

1. Oct 17, 2026, 17:01 UTC
   investigating
   We are investigating reports of delays affecting flow message sending. Some customers may see flow messages send later than expected. Immediate sends are not affected and are going out as expected. We will share another update as soon as we have more information.
2. Oct 17, 2026, 17:31 UTC
   investigating
   We are continuing to investigate delays affecting some flow email sending. Immediate sends remain unaffected. We will share another update as soon as we have more information.
3. Oct 17, 2026, 17:35 UTC
   identified
   We have identified the cause of the delays affecting flow message sending and are working on a fix. Some customers may continue to see flow messages send later than expected while we resolve this. We will share another update shortly.
4. Oct 17, 2026, 18:06 UTC
   identified
   We are continuing to work on the fix for this issue. Some customers may continue to see flow emails send later than expected while we resolve this. Immediate sends remain unaffected. We will share another update shortly.
5. Oct 17, 2026, 18:31 UTC
   identified
   We are actively working to clear the delayed flow emails and restore normal flow email sending. Some customers may still see flow emails send later than expected while this work completes. Immediate sends remain unaffected. We will share another update shortly.
6. Oct 17, 2026, 19:04 UTC
   identified
   We are still working to clear the delayed flow execution, and flow sending has not yet returned to normal. Some customers may continue to see messages send later than expected while we complete this work. Immediate sends remain unaffected. We will share another update shortly.
7. Oct 17, 2026, 19:42 UTC
   identified
   We are continuing to work on the fix for this issue. Some customers may continue to experience delays in flow processing while we resolve this. Immediate sends remain unaffected. We will share another update shortly.
8. Oct 17, 2026, 20:22 UTC
   identified
   We are continuing to work on resolving the delays affecting flow processing. Some customers may continue to experience delays in their flows while we work through this. Immediate sends remain unaffected, and delayed messages remain queued while we work to process them. We will share another update shortly.
9. Oct 17, 2026, 20:59 UTC
   monitoring
   Flow processing has resumed and the delayed backlog is actively clearing. This incident affected all flow processing - including flow-triggered email, SMS, WhatsApp and push messages, as well as flow updates to profiles and lists. Some customers may continue to see delays until the backlog fully catches up. Immediate sends were not affected. We continue to monitor closely and appreciate your patience throughout this incident.
10. Oct 17, 2026, 21:34 UTC
    monitoring
    Delays have now largely cleared, though some customers may still see flow messages send later than expected. We continue to monitor closely and appreciate your patience throughout this incident.
11. Oct 17, 2026, 21:51 UTC
    resolved
    Flow processing has returned to normal, and delayed flow actions - including email, SMS, and push messages, as well as profile and list updates - have fully caught up. Immediate sends were not affected. We apologize for the disruption this caused. This incident has been resolved.

Updates as published by Klaviyo (original).