Both full refunds, and partial refunds are taken care of by the plugin.

When an order is refunded, it will update the commission earned for that order, and also deduct it from the “unpaid commission” if it has been granted already (and not yet been paid out).

For partial refunds it will recalculate and only deduct commission for the amount that was refunded.

You can also use the “Delay Commission” option under “Payouts” to delay awarding them the unpaid commission for a certain amount of days, for example the length of your refund policy:

Amount-only refunds (PRO)

If you type a total into the refund box without allocating the refund to specific line items, there are no products for the plugin to recalculate from, so the commission stays as it was.

When the commission already granted to an affiliate is higher than the order’s current calculated commission, the “Coupon Affiliate” box on the order edit screen flags it with a one-click Deduct link. Click it to remove the difference from the affiliate’s unpaid commission balance and update the order’s recorded commission.

For more detail about how an order’s commission was calculated, see Commission Breakdown on Orders.