[Home](./index.md) > [@firebase/auth](./auth.md) > [PhoneSingleFactorInfoOptions](./auth.phonesinglefactorinfooptions.md) > [phoneNumber](./auth.phonesinglefactorinfooptions.phonenumber.md) ## PhoneSingleFactorInfoOptions.phoneNumber property Phone number to send a verification code to. Signature: ```typescript phoneNumber: string; ```