I had a terrible situation last night, and I'm trying to see if there is a better keyless entry system to prevent this sort of thing. I have a keyless/number pad lock on the unit. I change the code about every 4-5 weeks, but it is a pain b/c I have to make sure I've updated it in Airbnb and any saved welcome messages.... Plus, my place STAYS booked (100% occupied in March, with 2-3 night average stay), and turns over every few days. Yesterday afternoon, a young couple checked in. I spoke to them briefly, but they did not seem to want to chat. They did not state their names, but it would not have mattered. I do not greet them at check in 95% of the time. Later that night, a young woman sent me a message. She said she had just arrived and there was obviously someone staying in the room. The couple had unpacked, had showers, and gone out. The couple had mistakenly arrived a DAY EARLY! There reservation was for the following night. They had taken an Uber and were downtown. It was a really bad situation, and could have been much worse! I change the key code every 4-5 weeks. I'm afraid changing it any more frequently would cause more trouble. I'd like a "smart lock" that would send that day's check in guest a code. I don't want the guests to have to download apps on their phones or anything that assumes guests' tech saviness. Any help would be greatly appreciated!!