Hello @Paula-Boakes-Fairbrother0,
Typing "deposit" in the "Help" section search box showed up the article below.
How does Airbnb handle security deposits?
The security deposit is not charged at booking time. The guest is charged only if:
1) you make a claim within 48 hours of their checkout or before the next guest checks in, whichever is sooner;
2) all processes for making the claim are followed;
3) Airbnb decides, in their sole discretion, that the claim is valid.
There are very mixed reports on this forum as to which claims are entertained by Airbnb, how easy the process is and how satisfied hosts are with the outcome.
Steve.