We take your coupon offline when the budget is 80% utilized and we allocate the remaining 20% to cover for the redemptions of customers who have already clipped the coupon. For customers to have the best experience with coupons, we allow them to redeem coupons for a window of approximately 30 minutes after we disable the discovery of a coupon. In cases where 20% of your budget doesn't cover for the customer redeems in this 30 minute window, you might see your spend exceeding your budget. The risk of spend overshooting the budget decreases for higher budget amounts. For budgets under 1,000,000 JPY, you might expect a spend overshooting up to 15% (or more) of your budget.