This feature of whatsapp looks like a bad practice refering to the privacy of their users, I guess it has received critics about that and even though it's nowadays an old application it continues the same.

I think that something like relating an username to a certain phone number has to be easy, even trivial, sort of how a DNS works but whatsapp still stays the same, so my guess might be wrong.

Is there any reason that it is done this way?

  • 3
    I think it's because it's easy to setup email address and they try to minimize number of fake accounts, so they want people to have one account preferably with their real name.
    – Aria
    Sep 7, 2016 at 21:19
  • You might be able to ask them about this ...
    – schroeder
    Sep 8, 2016 at 7:22
  • I voted to close as off-topic. But if you edited to "What are the privacy implications of using phone number as user name?" - I think that would be a good question
    – paj28
    Sep 8, 2016 at 13:01
  • phone numbers are familiar, comfortable for folks to give out, and easy to read aloud over bg noise.
    – dandavis
    Sep 8, 2016 at 19:32

4 Answers 4


It's easy to use.

Everybody has a phone number, and you normally have the phone numbers of most people you want to chat with.

Therefore, you only need to allow WhatsApp access to your contacts and can chat right away.

This has of course some privacy implications, but the easiness seemed to be more inportant to the developers of WhatsApp than better privacy.

(And even the "private" messenger Signal asks for access to the contact list and compares it to the list of registered users... see https://whispersystems.org/blog/contact-discovery/ )


Like Aria said, to minimize fake accounts. But also, most phones have a phone number which allows you to use the app without providing any additional data. You can do so later on in the WhatsApp profile options, but that's bot mandatory.

In addition, using phone numbers let you connect easily with people already in the contact list. The app only needs to match those contacts with existing WhatsApp users.


Because they want to collect them. There is a rumour (I haven't checked if it is true) that some time before they have been collecting whole phonebook of users having whatsapp.


There might be an alternative reason.

A phone number may be only related to a SIM card (perhaps more accurately an IMEI). This gives opportunities to remain anonymous from the majority of people.

This is why, in many counties, the selling of mobile phones is fairly tightly regulated and you have to provide proof of identity. So that the government has the ability to relate the phone to a person.

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