Phone number as an alternative to email

Is your feature request related to a problem? Please describe.

• Not everyone has an email address, but many people have mobile phones.

• Email usage and accessibility vary greatly across different regions and cultures.

• People usually have one phone number, but might have many emails so they could for example vote multiple times.

Describe the solution you'd like
Make it possible for people to sign up for Decidim using their phone number instead of their email. Let the website's admin choose if people can sign up with email, phone, or both.

Configuration: an admin has a checkbox in the back-office allowing to enable/disable, email and SMS.

From the user perspective:

1. They come to the platform and want to sign up or login

2. If the admin allows to do so, they can now associate their account with a phone number instead of an email

Additional context
This proposal was accepted during the Decidim Fest (2024). The Brazilian platform team expressed special interest in this idea.

Does this issue could impact on users private data?
Yes, but likely positively.

Funded by
As mentioned during the Decidim Fest, this would be developed with the ressources of the technical team of Decidim.