I have multiple mobile numbers. Which mobile number will the verification code be sent to?

The verification code is sent to the mobile number added most recently to your OFX account. The 2-step verification popup will also show the last four digits of the mobile number OFX sent the verification code to, in case you’ve forgotten what number is tied to your OFX account. 

After verifying your mobile phone number, you can also complete your multi-factor authentication by setting up Google Authenticator from the Apple App Store or the Google Play Store.