I've given out 212-555-1234 as my phone number to so many random places, that I've accidentally given it out when I didn't need to hide my real number.

Also just about everywhere... (xxx) 867-5309 works for rewards cards and things like that. Also at Walgreens, you can use (420) 420-4204. That was the number the cashier gave me there since I told them I didn’t have a rewards card.

Just about everywhere: (local area code)-123-4567. 10 years ago I was almost always the only entry, if you're ever in the Cleveland feel free to use Aaaron ;-) If they don't like 123, use the store phone # prefix

I shouldn't have to lie. They didn't accept my "No.", nor that my full legal name was "Donald Fauntleroy Duck", until the case got escalated.