| Service | Category | Phone Required? | Can Transfer to New Number? | Multiple Accounts Same Phone? | How Peers Find/Address You |
|---------|----------|-----------------|----------------------------|------------------------------|---------------------------|
| WhatsApp | Messaging | Yes - sole identifier | Yes - built-in Change Number feature | No - one account per number | **Phone number** - contacts must have your number to message you |
| Telegram | Messaging | Yes - required for registration | Yes - full data transfer supported | No - but up to 3 accounts on one device with different numbers | **Username optional** - can be found by @username or phone number; phone # can be hidden |
| Signal | Messaging | Yes - primary identifier | Yes - Change Number feature preserves chats | No - one account per number | **Phone number** (username feature added recently but phone still primary) |
| WeChat | Messaging | Yes - required | Yes - via Settings | No (but 2023 update allows 2nd account under certain conditions) | **WeChat ID/QR code** - phone hidden by default; username is public identity |
| Venmo | Payments | Yes - required for verification | Yes - via account settings | No - unique phone required per account | **@username** - peers send money to username, not phone number |
| Cash App | Payments | Yes (or email) | Yes - via account settings | No - phone cannot be shared across accounts | **$cashtag** - unique username like $JohnDoe is the public address |
| M-Pesa | Payments | Yes - phone number IS the account | Yes - can transfer to new SIM at retail | No (Ethiopia: up to 5 accounts/name with shared balance) | **Phone number** - send money directly to phone numbers |
| Zelle | Payments | Yes - phone or email | Yes - can update in banking app | No - one account per phone number | **Phone number or email** - either works as payment address |
| Uber | Ride-sharing | Yes - primary identifier | Yes - via app settings | No - one account per phone number | **N/A** - drivers/riders matched by system, not direct addressing |
| Lyft | Ride-sharing | Yes - required | Yes - via app settings | No - one account per phone number | **N/A** - system-mediated matching |
| DoorDash | Delivery | Yes - required | Yes - via app settings with 2FA | No - explicitly prohibited in ToS | **N/A** - system-mediated; phone used for delivery contact |
| Tinder | Dating | Yes - required for verification | Yes - via account recovery or settings | No - one active account per phone number | **Profile/First name** - no usernames; matching is algorithmic |
| Bumble | Dating | Yes - required | Yes - via account settings | No - one account per phone number | **Profile/First name** - no usernames; matching is algorithmic |
| Slack | Productivity | No - email primary; phone optional for 2FA | Yes - can update 2FA phone in settings | N/A - phone not primary identity | **@display name** within workspace; email for invites |
| Notion | Productivity | No - email primary; phone optional | Yes - can update in settings | N/A - phone not primary identity | **Email** for sharing; display name within workspaces |