Hello everyone, I am a host in Greece. In my country we MUST declare the money we received untill the 20th of every month on the Tax Bureau web site. They just ask the full name of the guest, his/her s passport number , the dates of their staying and the amount. If we don t , they will find out and then you pay a penalty on top because of NOT declaring !! In Greece we taxed a 15% up to 12000 euros and more after this amount and this is SEPARATE from other money you make i.e. as a worker, a businessman , unemployed etc. Giving your passport number is safe, we give it to the tax bureau and that s it. thank you for helping us.