Adjustments can happen for a number of reasons and occur anytime. In order to account for these adjustments to previous monthly earnings, Sovrn //Commerce always pays based on lifetime earnings and previous payments. The most common adjustments to publisher earnings are related to sales returns or late revenue approvals by the merchant, causing previous earnings to either increase or decrease depending on the circumstance. Although these can happen at any time, most adjustments occur within 2-3 months after the month of earning.
Certain verticals tend to see adjustments later than others. I.E. Many affiliate programs for travel merchants are confirmed upon trip completion instead of booking date. If a commission was earned for a hotel stay in 4 months, it leaves a longer window for a commission to be adjusted.