A paid order’s total never changes silently. When a change lowers or raises the total, the money is settled automatically.
| Situation | What happens |
|---|---|
| Unpaid order (Pending payment, On hold) | Totals, taxes and shipping are recalculated. If payment is due, the customer goes straight to the payment page. |
| Paid order, lower total | The difference goes back through the payment method automatically. If the method cannot refund online (for example bank transfer), you get an email to refund it by hand. |
| Paid order, higher total | The customer pays the difference first in a separate payment. The change is applied only once it is paid. The original order shows a “Paid separately” line so both orders add up to what was paid. |
| Pay on delivery (Cash on delivery) | Nothing is charged or refunded online. The amount to collect simply changes. |
Free: on paid orders customers can change the address, delivery option and product options (for example size). Pro adds products, removals and quantity changes on paid orders, settled the same way.
Stock
Only the difference moves. Changing a quantity from 3 to 2 puts one item back. Adding a product reduces its stock. Orders where WooCommerce has not reduced stock yet are left for WooCommerce to handle at payment. WooCommerce’s own stock records stay correct for later refunds and cancellations.
Delivery costs
When products or the address change, delivery costs are recalculated from your shipping zones, the same way as at checkout, including free shipping minimums. If the current option no longer applies, the customer is asked to choose another.