Payment refunds and reversals from PayPal do affect affiliate commission earnings, as long as you have not already generated the
masspay.txt file to pay out commissions for the month when the original sale occurred.
When you go to Seller Admin > Manage Affiliate Program > Pay Your Affiliates to obtain your monthly commission report, that generates a fresh
masspay.txt file based on the current state of your Transaction Log at that moment for sales in the selected calendar month. However, if anything affects that month's sales after you generate the masspay file, those changes will not be carried over into the next month's commission calculations.
For instance, payments from the completed month may get refunded or reversed, or if you had a payment funded by eCheck late in the month, it could take several days into the next month for that check to clear. However, if you have not yet submitted the masspay file to PayPal, you can always regenerate a new masspay file for that month again, which would recalculate commissions to account for any late-breaking changes. For this reason, we recommend generating your masspay file in the last half of each month, which should allow plenty of time for eChecks to clear or any refunds or reversals to be processed.