This is related to a food ordering/takeout mobile app. Currently, users create an account immediately in order to access the app, and it is required that they verify their phone # to prevent duplicate accounts. What is more likely to retain users/will cause less abandonment:
This question will likely generate opinion-based answers.
Here's one: phone verification should be performed during signup, when you're already asking for personal information. That way when the user is hungry and uses the app, they won't have an extra hurdle to go through to get their order in.
I'm personally more an advocate of asking details "just-in-time". This way your users can first browse the kind of food that is offered on the platform & your value proposition, so they're convinced enough to actually order and provide their phone verification.
So, my opinion is, use the second option as this lowers the initial hurdle of browsing through your app & let the hunger convince them to verify their phone number.
I would say the second option is less of a barrier as the user would have already committed some time within the app.
Furthermore, it's always a good idea to give the users a "permissions primer" (see this article for guidance) conveniently placed before the event. In essence, you must focus on showing the user the value of giving away their phone# e.g. Do you want to be notified if your order is delayed or when the order is outside your apartment block? Then shuttle them to the permissions dialog.
"Ask them to verify their phone during the account creation/sign up process." because when they verify their phone number during sing up process than they surely verify it. 92% users can make full constraint on signup process that time is perfect for number verification.
