Best Practice
Freight is added as a Non-Inventory Class product on a Purchase Order, receiving it together with the other items being received (via the Supplier-Invoice Process).
Applying freight in this way will ensure you have control over the freight cost you are applying to your Purchase Orders, especially if you are receiving part shipments.
It's recommended that you are familiar with the Supplier-Invoice Process.
Why?
By applying your freight costs via the Purchase tab of the Purchase Order, the freight will not batch to your accounting packing until the Purchase Order is closed. Using this method may result in orphaned freight costs in your accounting package when the Purchase Order finally closes.
If you must enter a Freight Cost on the Purchase tab of the Purchase Order, make sure a Freight Packing Slip is selected to ensure that freight is posted together with the items being received. Failure to select a Freight Packing Slip will result in ConnectWise setting a default (the Purchase Order Number) value.