What happens if I don't put the proper shipping weight as a seller? Understate the shipping weight?

Bevv will invoice you for the difference. UPS will invoice Bevv and we will invoice you. 

We require immediate payment of invoices as it impacts our operating costs. Unfortunately (we don't expect this to happen), if invoices on shipping aren't paid then we will be forced to send to collections. 

Don't forget to take into account when determining shipping = weight of the product + weight of the box + weight of the packaging.