Who this is for

If your team is manually typing the same freight, duty, or handling charges onto every purchase order or shipment, this article shows you a faster way. Cost rules let you define a charge once and have it appear automatically on every matching PO.

Common situations where this helps

  • Ocean freight on overseas POs — you pay roughly 8% of goods value in freight on every container from a specific supplier.
  • Import duty by category — a fixed duty percentage applies to a whole product category.
  • Flat handling or drayage fees — a $250 dock fee applies to every shipment from a certain warehouse or supplier.
  • Mode-specific charges — air shipments carry a surcharge that sea shipments do not.

How you would use it

  1. Go to Inventory → Inventory Admin → Cost Rules and create a rule with the type "Add extra cost line."
  2. Choose when it fires using Conditions — for example, only for a specific supplier, destination warehouse, or shipment type (Air, Sea, Road, Rail, Express).
  3. Choose what it charges using the Cost Basis:
    • Percentage — e.g. 8% of the value of matching items on the order.
    • Fixed amount — e.g. a flat $250 per order or shipment.
  4. Optionally turn on Auto-apply on save. With this on, the charge is added automatically every time a matching PO or shipment is saved. With it off, the rule appears as a suggestion you can review and add with one click using the preview button.

Why teams use this instead of manual entry

  • Consistency — the charge is never forgotten on a busy day, and it is always calculated the same way.
  • Accurate landed costs — these charges flow into your landed cost at receiving, so inventory value and margins reflect the true cost of goods.
  • Less data entry — the team stops re-typing the same charge on every document.
  • Safe rollout — rules start as preview-only suggestions. Nothing is added automatically until you explicitly turn on auto-apply for a rule.

Good to know

  • Costs added on a PO are estimates. They become part of your actual inventory cost when goods are received.
  • When you create a shipment from a PO, the PO's extra costs carry over to the shipment automatically.
  • If a rule adds a charge you don't want on a particular order, you can simply delete that line from the order — manual edits always win.
  • "Can freight be added to POs automatically?"
  • "How do I stop my team from forgetting to add duty charges?"
  • "Can I charge a fee only on air shipments?"