I\'m working on Express Checkout integration, and have everything working without any technical problems. The only issue is that we need to have the buyer\'s phone number.
You can find this under 'Website Preferences' in your PayPal account's profile.
The direct link to this page is https://www.paypal.com/cgi-bin/customerprofileweb?cmd=_profile-website-payments.
In Sandbox this will be located here:
https://www.sandbox.paypal.com/businessmanage/preferences/website
Selling Tools
> Update
> Scroll down to contact number and select your preference.
I have created a video walkthrough to demo to do this.
https://youtu.be/xifEOswaljc
If anyone is still having trouble getting the phone number: even after I made the prefs change suggested above I couldn't see it in the payment response, but it IS available via a request to /v1/payments/payment/PAYMENT_ID via the REST API. Payer-PayerInfo->Phone.