We are working on a mobile app that offers 'give and receive' advice (concerning relationships, life questions, and so on). In the onboarding flow, we allow users to choose how to create their account - via email & password or phone number. Our management team insists on asking the user for their email address if they chose to create an account using their mobile number. I already know when to ask this (after they approved the OTP code we sent them), but not sure how to do it - how to present it or even phrase my request? In most cases, the user does not expect to also share their email if they just signed up using their phone number...what do you think is the best way to do this?

  • Hi Noa, what have been your ideas so far for phrasing and presenting it?
    – Nash
    Apr 25, 2021 at 12:47
  • Hi Nash! That's what I wrote: Title: "Your phone number was successfully verified" Body: "Please enter your email address to complete your account and sign up:" email field CTA - "Done" (that's the last screen out of 3 when they tap 'continue' each time to progress. I also added a green 'check' icon above the title.
    – Noa.R
    Apr 27, 2021 at 12:26
  • Not addressing the UX aspect, but you might want to have a look at Prevent against OTP abuse in app sign up flow on the Security SX... essentially, if you're going to be asking for emails anyway, always doing so first may save you from someone trying to abuse your sending of OTP messages.
    – TripeHound
    May 16, 2023 at 15:31

1 Answer 1


As per my understanding of the use case, in both the cases the end user's email is mandatory. So, you can try to approach a way where both phone and email id should be asked while registering so that it will reduce the additional step when user opt for registering via phone number.


After the OTP approved, you can ask them like "Login with your email account and enjoy the experience"/ "Happy to know about you and help you" and ask the first name, last name and email.

Hope this helps.

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