You have 15 days from when you were approved to drive for Uber to still use an Uber Referral Invite Code and still receive a sign up bonus.
If you want to use an invite code that you did not apply during sign up, contact me. You will need to visit the Help section in the partner app or on help.uber.com to report your missing referral:
How to complete the missing referral form
Payments > Driver Referrals > Report a missing referral
- You will need the email and phone number of the person that is referring you.