Hey @btran, welcome to the Seller Community! 

So the Square Contactless and Chip Card Reader is universal. They are not connected to an account. The reader can only be connected to one device at a time. 

If you plan on having people take payments upon your behalf take a look at our Employee Management feature. Each employee will get their own login so you can differentiate the sales amongst them. All of their sales will deposit into your linked bank account. You can also limit what they can see on the account using permissions. For example you can make it so they can only process sales. 

Please let me know if you have any other questions! 😀