Legal paperwork required to start an Airbnb business.

Contact the local government office. Rules vary widely between jurisdictions. You probably also need a Hungarian business to be able to rent, even through AirBnB, so you pay all appropriate local business and income taxes. Each town or city in Hungary can legislate their own local taxes for anything.

Be aware, there is a national overnight guest tax that AirBnB may not collect but you are responsible for. Be sure you pay it.

Also, you should ask the building owners, if any and if you do not own the entire building, or building coop board if one exists. They may not allow such short term rentals.

Yes, great advice again.
Be sure to check with your house management to make sure they even allow such a business in the house.
I am pretty sure we agreed to not do such a thing when we bought our flat 11 years ago but since then a large apt. next door and above our neighbor as turned into a B&B after getting remodled.
This neighbors MIL has lived in the house since she was born 73 years ago. He is a assistant manager and doesn't take any thing off of anyone in the house. I even witnessed him and his son physically sitting on 2 Gypsies who entered our building the day we moved in, they questioned them as to what they were doing in the house etc.
Even saw him put his hands around another persons neck another time.
So no messing about with him.
His MIL really is upset about the B&B because people come home late at night and wake her up.
We had a yearly house meeting last week but as usual only about 5 people go.
My husband used to go but alone, his vote doesn't count much and he doesn't want to make waves by himself, no need to get sat on or strangled.
We should get the memo soon about the new votes for the house, might be bye-bye for the B&B since his MIL is upset about it.
Then again, he may be charging a kick back for his troubles.
Not all residents will enjoy having strangers coming and going with keys to the building at all hours of the night.
Not even sure how this new apt. owner got away with starting the B&B in the house to begin with.
If it stays open, we may think of doing the same with our flat, never know could be a money maker short term.

Dear Klsallee,
Thank you very much for your response. I will keep your pointers well noted as gather more info.
Have a great weekend 😀

Thanks a lot Marilyn for the starting points. I second you on the fact that the building management does indeed plays a crucial role in taking the Airbnb off the ground. I will check on that as well .
All the best and appreciated your assistance 😀

Did you finally go ahead and register your apartments as Airbnb's?  We are looking to do this as well but were wondering how we go about it.