I'm a long-time Republic Wireless customer. As such, by definition, my phone number is a mobile number. But not according to Venmo. After I sold an item to someone who wanted to pay by Venmo, I tried to open a Venmo account. But they rejected my application, saying my number was a "landline" number. I tried, repeatedly, to see what evidence I could offer so I could open an account, but they just kept falling back on the landline bit. I can only conclude that they'll let you open an account with SOME carriers' mobile numbers, but not mine.