Slack incident
Free Plan Customers Are Experiencing Message Failures
Slack experienced a minor incident on October 1, 2026 affecting Messaging, lasting 6h 20m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Oct 01, 2026, 12:39 PM UTC
We're aware that some customers on our free plan are experiencing message-sending limit blocks in an unusual spike pattern, which is preventing them from sending messages. We're investigating why this message limit was triggered unexpectedly for some teams. If you're affected, you may be temporarily unable to send messages until this is resolved. We'll provide an update in 30 minutes or sooner if additional information becomes available.
- investigating Oct 01, 2026, 12:56 PM UTC
We identified that a third-party app is stuck in a loop that has triggered billions of messages. This is causing free plan users to exceed messaging limits. We apologize for the inconvenience and will provide another update as soon as we have more details to share.
- investigating Oct 01, 2026, 01:58 PM UTC
A feature toggle ramp-up caused an app integration to repeatedly post messages in a processing loop. This pushed free plan customers over the message volume threshold, triggering the sending block. We're working to restore access and are actively working on remediation options for impacted Workspaces. We apologize for the inconvenience and will provide another update as soon as we have more details to share.
- investigating Oct 01, 2026, 02:31 PM UTC
We’ve identified a potential fix for this issue and we’re working on getting this out to users as quickly as possible. We’ll be back once we have another update to share. Thank you for your continued patience as we work towards a solution.
- monitoring Oct 01, 2026, 06:52 PM UTC
Deployment of the fix is underway to restore access for impacted free plan workspaces, and we are actively monitoring the environment. More information will follow as we progress through this stage of remediation.
- resolved Oct 01, 2026, 06:59 PM UTC
A messaging integration briefly caused some free-plan workspaces to exceed their daily messaging limit, blocking them from sending messages. We took action to lift the sending block for all affected free-plan workspaces, and have confirmed messaging is now restored. We apologize for how this incident affected you and your business. We will undertake a full investigation of the incident, establishing the technical trigger, the underlying cause, and preventive action to avoid a repeat in the future.