Sunday December 4, 2022


Issues with SMS two-factor authentication for some customers

Issue summary:
On December 4, 2022, from 5:00 PM PST to 11:14 PM, users ran into trouble where they did not receive 2FA codes on SMS, making them unable to log into Slack as a result. This issue was due to a service provider's slow processing rate.

To fix this, we sorted out the processing backlog together with the service provider. We then had them raise the country specific processing rate limit, resolving the issue for our customers.

1:59 AM PST

Thank you for your patience. The issue with login functionality should now be resolved. The service is back and you should be able to receive SMS 2FA code by retrying.

Please let us know if you are still running into any issues. We apologize for any disruptions to your work day!

11:46 PM PST

We're sorry for the inconvenience, but we are continuing to experience the issue with login functionality. We're working hard to resolve the issue as quickly as possible and we'll be back with another update in 30 minutes.

10:34 PM PST

While we don't have additional news to share, we are still working away to get things back in order for you. Stay tuned, we'll post another update in 30 minutes.

9:48 PM PST

We're continuing to make progress, but we have no new information to share at this stage. We apologise for the ongoing disruption — please stand by for another update in 30 minutes.

9:17 PM PST

We’ve identified what’s causing the SMS two-factor authentication issues. We are continuing to work towards a fix. We’ll provide another update in 30 minutes. Thank you for your patience!

8:40 PM PST

We’re still working to resolve the issues with SMS two-factor authentication. We’ll continue to provide updates every 30 minutes.

7:56 PM PST

We are still actively investigating the issues with SMS two-factor authentication. We’ll be back with another update in 30 minutes.

7:23 PM PST

We're investigating issues with SMS two-factor authentication. Some customers may be unable to login to Slack.

You should still be able to login using your backup codes. We apologise for the disruption, we'll be back with an update as soon as we have more information.

5:53 PM PST

Services affected