Contact Host allows you to send an enquiry to the host and is in no way a booking request. You should always do this before committing to a booking to ensure the place is actually available.
Request to Book commits you to a booking and your card is charged there and then, regardless of if the host accepts your request. It then takes up to 7 days to get your money back if the host declines - pretty frustrating.
Instant Book means the host can't decline your booking without their search ranking score being negatively affected.
1) Enter dates
2) Pick Place
3) Pick "Contact Host"
4) Host says place is as available
5) Get message from AirBnB saying I've been approved by host
6) Get message from AirBnB saying host has charged my card
At no time did I pick "Request a Booking". I thought it would stop at #5 and I'd have to then login to AirBnB to finalize the details but no, the host was able to do that without me even though I never picked "Request a Booking"
This isn't the expected behaviour because step 5 would mean that the host had sent you a Pre-Approval - this usually requires you to take action to confirm the booking and reach step 6.
I've used AirBnB 18 times in the last 2.5 years. It happened. Give me your credit card. I'll go through the process and see if I can get you booked. I'll video all of it.
Or if you're from AirBnB, give me a fake account and all make it happen again. If you think this is how it works I'm telling you there's a bug in your system
It doesn't quite commit to you to a booking: at any point before the host accepts the request, you can cancel the request penalty-free [1]. So if you find something better in the meantime and change your mind on the AirBnB place, you can just cancel. It is however a bit risky, since there's always a chance that the host will accept RIGHT as you were about to go cancel. And having two requests outstanding bears the risk that you'll get unlucky, and they'll both accept so close together that you have no time to cancel the other one.
So now we need to create a web service to send multiple requests and auto-cancel when the first one is accepted. The chance of auto-accepting within the minutes needed to respond should be small, unless you sent to the same host multiple requests.
Contact Host allows you to send an enquiry to the host and is in no way a booking request. You should always do this before committing to a booking to ensure the place is actually available.
Request to Book commits you to a booking and your card is charged there and then, regardless of if the host accepts your request. It then takes up to 7 days to get your money back if the host declines - pretty frustrating.
Instant Book means the host can't decline your booking without their search ranking score being negatively affected.