A pre-approval is a way for a host to let you know if their listing is available for the dates you’ve inquired about. Once you're pre-approved, you can automatically book your reservation for those dates without waiting for another response from your host.
Keep in mind that when a host sends you a pre-approval, your booking isn’t confirmed until you’ve clicked Book It in your message thread and added your payment information. Hosts can send pre-approvals to multiple potential guests, so if you’ve found the perfect space, make sure to complete the booking process as soon as possible.
You have 24 hours to accept a pre-approval before it expires. If more than 24 hours have passed, you can still accept the pre-approval, but your host will need to approve your request before your booking is confirmed.