Yes, it matters which phone you use because the system cannot recognize you if you call from a phone that isn't set up on your account. Phone numbers are associated with users on your account, so you can add a second person with their own mobile number (see How do I add another user or phone number to my account?). You can also add yourself as a second user using the same name and license plate number, but you will need to use a different email address. You can have up to five users on one Parkmobile account.
When calling from a number that is not associated with an account you will be prompted to register or to enter the mobile number of your existing account. If you choose to register, the phone number from which you called will be associated with your account, so please be sure to call from your mobile number to register. It is important to register your mobile phone number rather than some other number which may be a shared or public number. Registering a phone number that isn't uniquely yours will allow anyone calling in from that number to start parking sessions on your account. If you choose to register a phone number other than your mobile number, such as your office number, please be sure that the outgoing number transmitted when you place a call from that phone isn’t a shared number, main office number, or a number that would represent any calls from your office, regardless of the phone used to place the call (also known as a “trunk” number).