The mobile number that I used for my PayPal account was lost and now PayPal wants me to enter a code that it sends to that number, for log-in. What can I do now?
You need to contact customer services to resolve any account specific issues. Click help / contact bottom left of Paypal pages for options available for your country.
Or have you considered contacting Customer Service via Facebook or Twitter? You can send them a personal message from their facebook or twitter pages. It's: https://www.facebook.com/PayPal and @AskPayPal for Twitter.
Advice is voluntary. Kudos / Solution appreciated.
