You have 2 days after your event to hand the kit to a carrier. Not to have it arrive — just to hand it over. The clock stops at the first scan.
Past that it is $75 a day. That is not a penalty for its own sake: each kit serves one event at a time, and a late return can cost another couple their date.
If something outside your control delays it — a carrier closure, weather — tell us before the window closes and we will not charge it.
Two minutes, and you'll know either way.