How to stop double bookings in a car rental business
Double bookings are not a memory problem, they are a system problem. Here is where they actually come from and how to close each gap.
Every rental owner has done it once. A customer confirms for Saturday, you write it down, and
three days later someone asks for the same van on the same Saturday and you say yes, because
the first booking was in a different place from the one you happened to check.
It is worth being precise about why this happens, because "be more careful" has never fixed it
for anybody.
Double bookings come from having more than one source of truth
If your bookings live in a notebook and a Messenger thread and a Google Calendar, you do
not have one schedule. You have three, and they are only correct when all three were updated at
the same moment by the same person. That happens about as often as you would expect.
The fix is not a better calendar. It is having exactly one place where a booking is real, and
treating everything else as a copy that might be stale.
