Why am I getting "Invalid OTP" errors when trying to sign up or log in?

Last updated: January 29, 2026

Context

You're trying to create an account or log into Sync.so using email authentication, but when you enter the One-Time Password (OTP) code sent to your email, you receive an "Invalid OTP" error message. This prevents you from completing the signup or login process.

Answer

There are several common causes and solutions for invalid OTP errors:

1. Email Provider Restrictions

Hotmail/Outlook emails are currently disabled for signup. If you're using a Hotmail or Outlook email address, try one of these alternatives:

  • Use a different email provider (Gmail, Yahoo, etc.)

  • Sign up using Google SSO instead of email authentication

2. Browser Issues

Browser extensions or cached data might interfere with OTP validation:

  1. Try signing up/logging in using an incognito/private browsing window

  2. Disable browser extensions temporarily

  3. Clear your browser cache and cookies

3. Email Delivery Issues

If you're not receiving OTP codes at all:

  1. Check your spam/junk folder

  2. Try clicking "Resend OTP" and wait a few minutes

  3. Ensure your internet connection is stable

4. Custom Email Servers

If you're using a custom company email server, the emails might bounce due to server configuration issues. In this case, try using a personal email address or Google SSO for authentication.

5. Alternative Login Method

If email OTP continues to fail, you can use Google SSO as an alternative login method, which bypasses the need for email-based OTP codes entirely.

If none of these solutions work, the issue may be temporary due to system limits or maintenance. Wait a few hours and try again, or contact support for further assistance.