How you can cancel a reservation varies depending on what stage the reservation is in.
Is your reservation request still waiting for landlord approval? Then you can simply cancel it directly from your My Housing web app!
However, suppose the owner has already approved your reservation request, and you are no longer interested in it. In that case, you can still cancel the reservation before you sign the lease agreement. Just consider that you should do this only in essential cases. Because when the landlord accepts your reservation, their property is stopped being advertised, and they can lose the chance to rent their property to someone else.
Do you have an approved reservation and also a valid agreement? In order to cancel your reservation, contact Flatio customer support well in advance of your contract beginning (the specific time and amount of refund depends on the type of cancellation policy).