The deposit is never deducted upfront, it is more of a safety measure which allows you to open a claim within 48 hours of the guest checking out in the event of any damages. If you put in a claim, Airbnb will e-mail the guest with details and if the guest accepts/ if Airbnb find in your favour then only then will Airbnb charge their card.
Lick on the Help option, you will find basic info as such to familiarise yourself; click on the link for a brief - guide https://www.airbnb.co.uk/help/article/140/how-does-airbnb-handle-security-deposits
All the best with your first hosting experience on ABB
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