Open WhatsApp
Tap the three dots or Settings
Tap your profile name or photo
View your phone number under your profile info
If needed, ask the person to share their number directly in chat
Check the contact details saved in your phone
Use the contact card if the number was shared to you
If you are trying to find your own WhatsApp number, open your profile in WhatsApp
If you are trying to find someone else’s number, check the chat header or shared contact info if available