[] Auth iOS verifyPhoneNumberWithMultiFactorInfo invalid-phone-number error

Author: bthurlowCreated Dec 30, 2023Updated Aug 26, 2026
Labelstype: bugplatform: iosplugin: authenticationblocked: firebase-sdkKeep Open

RN: 0.72.7 RNFB: 18.7.3 iOS: 17.x

There appears to be an issue with the decoding of the MultifactorInfo on iOS when performing the MFA sign-in flow, this code is working on Android, but on iOS it appears that the phone number coming over is formatted as +*******1234 and in turn is throwing the invalid-phone-number error when calling the verifyPhoneNumberWithMultiFactorInfo method.

Tested on device and simulator with the same result.

The code below is based on the official documentation from here: https://rnfirebase.io/auth/multi-factor-auth

javascript
const mfaResolver = auth().getMultiFactorResolver(error);
            if (mfaResolver?.hints[0].factorId === auth.PhoneMultiFactorGenerator.FACTOR_ID) {
              const hint = mfaResolver.hints[0];
              const sessId = mfaResolver.session;
              auth()
                .verifyPhoneNumberWithMultiFactorInfo(hint, sessId)
                .then((vId) => {
                  setVerificationId(vId);
                  setMfaResolver(mfaResolver);
                  setShowVerificationForm(true);
                })
}

Ideas or assistance is appreciated.

Source: invertase/react-native-firebase