If you are going to update your Aadhaar card, then definitely know these rules. The names in the Aadhaar card can only update twice, for which you will have to provide documents like marriage certificate, passport, PAN card or voter ID. Dob (Date of Birth) You can change only once. But how many times you can update free from the official website of UIDAI. There is no limit to change mobile number and email id, but for this you have to go to the Aadhaar service center and update. No document is required for the mobile number update, and OTP comes to the same number, so the registered number is very important.