If you've set up your mobile number as the multi-facto authentication (MFA) mode for your Zoho account, you will receive a one-time password to your registered mobile number when you to sign in to your account.
To register your mobile number for MFA:
- Sign in to your Zoho account.
- Click Multi-factor Authentication on the left pan menu.
- Click Setup Now under Mobile-based OTP.
- Enter your mobile number, then click Next.
- Enter the OTP sent to your mobile number, then click VERIFY.

If you are switching mobile numbers for MFA, add your new mobile number before your remove your old number.
To sign in using your mobile number:
- Go to Zoho Accounts.
- Enter your email address, then click NEXT.
- Enter your password, then click SIGN IN.
- Enter the OTP sent to your mobile number, then click VERIFY.