This is not so much a question as a post to help others who have run into this issue.
This was my situation: I had created an invoice on my laptop and I wanted to include the recipient's phone number. Despite selecting their country from the dropdown next to the phone number field (they're American; I'm Canadian), I received an invalid phone number message. The phone number was 10 digits long. Inserting spaces or dashes didn't help.
I searched the PayPal community forum before deciding to contact PayPal via the message centre. after a thoroughly unsatisfactory and unhelpful session there (the best they could do was tell me to clear my cache) and having the customer satisfaction survey crash on me, I decided to contact PayPal over the phone to, at the very least, report my dissatisfaction.
The agent I spoke with, Tessa, was much more helpful. She informed me that whenever a contact email address is entered on an invoice, PayPal runs a check on the phone numbers in the account profile associated with that email address. If the number entered doesn't match what’s in the profile, the seller sees the invalid number error message. So, if a seller has a) changed their phone number since they set up their PayPal account and not updated their profile or b) listed a landline number on their account, but given the seller a cell phone number instead, the seller will receive the error.
Currently, there is no “fix” for this problem.
