You have two days I think. I emailed the POC on the packet that arrived by FedEx and stated: I am on a trip and won't be home for 3days. I also said there was a testing facility down the street from my overnight but I wouldn't have my paperwork. She replied and said it will be fine if I just wait and do it when I get home. But I would at least email her so it is documented why you are late returning it.