[Home](./index.md) > [@firebase/auth](./auth.md) > [PhoneAuthProvider](./auth.phoneauthprovider.md) > [providerId](./auth.phoneauthprovider.providerid.md) ## PhoneAuthProvider.providerId property Always set to [ProviderId.PHONE](./auth.providerid.phone.md). Signature: ```typescript readonly providerId = ProviderId.PHONE; ```