Sign-In Error
Slack Software
Severity: MinorWhat Does This Error Mean?
Slack shows a sign-in error when the email, password, magic link, or two-factor code did not validate.
Cause is usually a code that timed out, an old magic link clicked too late, or a 2FA token from a stale authenticator.
Most cases clear by requesting a fresh code or magic link and using it within the time window.
Affected Models
- Slack desktop on Windows, Mac, Linux
- Slack iOS app
- Slack Android app
- Slack in browser
Common Causes
- Magic link clicked after expiry (60 minutes)
- Verification code typed after expiry
- Two-factor code from authenticator out of sync
- Wrong email address typed
- Password recently changed but old one was used
- SSO provider down (for enterprise workspaces)
How to Fix It
-
Request a fresh code or link.
If the magic link or code expired, click 'Send another' or 'Resend' on the sign-in screen.
A new code or link arrives within a minute.
Use it immediately — Slack codes are short-lived for security. -
Check inbox and spam.
Slack emails sometimes land in spam, especially on corporate inboxes.
Search your inbox for 'slack.com' or 'verification'.
If still missing, ask IT to allow Slack's email domains. -
Check authenticator time sync.
If you use TOTP 2FA (Google Authenticator, Authy, 1Password), the codes change every 30 seconds and depend on accurate device time.
Settings → Date and time → Set automatically.
Authenticator codes from a phone with skewed time are rejected. -
Try a different sign-in method.
If you have multiple ways to sign in (password, SSO, magic link), try a different one.
SSO problems can be bypassed with email magic link.
Password problems can be bypassed by requesting a reset. -
Reset password.
If password is the suspected issue, click 'Forgot Password' on sign-in.
You receive a reset email.
Set a new strong password.
Sign in with the fresh credentials. -
Use backup codes for 2FA.
When 2FA was enabled, Slack provided backup codes.
If your authenticator is lost or broken, use a backup code from where you saved it.
Each code works once.
After signing in, regenerate fresh backup codes from settings. -
Contact admin for SSO issues.
If your workspace uses SSO and the SSO provider (Okta, Azure AD, etc.) is failing, you cannot sign in until they fix it.
Notify IT.
Use Slack mobile via direct password if backup access was set up.
Frequently Asked Questions
How long do magic links stay valid?
Slack magic links expire after 60 minutes.
If you click an old link, you get a sign-in error.
Always request a fresh link if more than an hour has passed.