We are trying this for a little while, hopefully it works out.
If you have a order PROCESSING, meaning a label has not been shipped you can place subsequent new orders and use the “ADD TO…” option to pay .00 on items to add to the pending order. When we print labels each day, we will first check for combinable orders. We will not refund any past orders for combines, as it takes way too much time away from employees filling orders. If you make an ADD TO order, and there are no Paid shipping orders processing, that .00 shipping order will hold/wait until a new PAID shipping order has been made, and then it will be combined.
This is for USA only.
*NOTE* For a combine to show up in ShipStation, all orders must be made with same account/login/email and the addresses have to be EXACT include captialization.