PayPal orders come in without any phone number information.
Note: By default, PayPal does not require the phone number to be captured when the customers tries to checkout from the site.
Enable this in PayPal to ensure that all orders will have phone numbers:
1. Log in to PayPal Merchant Account
2. Under My Account tab, click Profile sub-tab
3. Click My Selling Tools
4. Click Update next to Website Preferences
5. In the Contact Telephone Number section> select On (Required Field)
This would require customers to enter phone numbers in PayPal and will be captured in the Address tab in NetSuite.