This is normal information in many European countries for hotel or other rental accommodations. If there is an alternate key pickup for your lodging where you don’t meet the owner, it ensures that they get the proper info to comply with local laws.

Thank you, Philip for your response. I guess it is not the requirement of the info that I am questioning but rather the requirement that it be done BEFORE arrival and via the internet. In the past, this info has been given in person upon arrival and never was requested ahead of time. I am not keen on putting this info in an email or over the internet.

Technically, in Budapest, the information has to be in the government computer system prior to you going thru the door. It's a hassle and time consuming and it sounds like your host is just giving himself time to do it. Good news is they wouldn't be asking if the unit wasnt being legally operated. Still quite a few illegal operators in town. Always look for the registration number in the listings, required by law.

Are they asking for more than name, passport number, and contact info?

Hi Mr. E, thank you for taking time to assist me. Something stood out in your answer to me. It was this:
" they wouldn't be asking if the unit was being legally operated". Did you mean that? That indicates that this airbnb might NOT be legally operated. We have already booked it (paid in full some time ago). Also
as I noted, I tend to be overly cautious (sorry, but there ARE a lot of scams everywhere) and to add to my
hesitancy about sending such info through emails/internet, this very Airbnb just had a hack into their messaging platform and if I had not been the cautious type I might have really gotten scammed. (it involved payment info). The
person who runs or operates the apartment messaged back that all was okay and I had no need to worry it was just a hack into the airbnb messaging. We are always told to use that avenue to message for security and safety! Now I really do not know what I should do. Any other ideas or something to ease my mind?
I only know that the info initially asked for was the kind of things you would get with a passport or driver's license but he has sent a video on how to proceed but it looks like it is not in English and seemed rather
involved. I need to look at it more closely. Still your statement about the authorities would not ask for
my info if it was being legally operated has me wondering how to proceed.

Hopefully Mr E will come back soon to confirm, but my guess is that he made an error and meant to write they wouldn't be asking if the unit was being illegally operated.

Hello Dutch_traveler. Yes, I have to think that is what he meant. But I do not want to assume anything.
He seems to have so much good ideas about Budapest and Hungary and I am grateful for his insight and for your chiming in as well.

It appears Budapest requires shott let apartments to register. Check the listing you reserved. There should be a published registration number. If not, request one from the host prior to completing the form.
The fact they are trusting the form to be completed, I would expect the rental to be above board...but that registration number will tell you.
As for as completing the form, it is difficult if over cautious. Sometimes things just have to be done. I assume you are not the first to book this place. If it has numerous good reviews and the host has been on the platform for a while, then you may need to be a little more trusting. Of course, there is also the fact that AirBnB platform has been in place 25 years (ish).

Thank you, MariaF for your input and advice. I will check for that registration number. That would give me some peace of mind.

I figured given the time difference for Mr E to respond, I would give you something to work with. Good luck.

Yes, it was just a typo or an unhelpful autocorrect.

Hi Mr. E, thank you for taking time to assist me. Something stood out
in your answer to me. It was this: " they wouldn't be asking if the
unit was being legally operated". Did you mean that? That indicates
that this airbnb might NOT be legally operated. We have already booked
it (paid in full some time ago). Also

YIKES! KILLER TYPO. FIXED

Without knowing what they are asking for it'd gard to comment on. At a minimum they need name, passport number and contact info. The government website they have to enter it into isn't user friendly so most want it prior to arrival, as it must be complete before you enter.

In Budapest if there is ever a listing without the registration number, don't request it, just move on as it's required to be in the listing.

Thank you Mr. E. I think we all kind of figured out what you really meant. Being someone who seems to always be hitting the wrong key when typing, i have "been there, done that".

If you can give the name or location of this fine establishment, I maybe can tell you what of interest might be in the neighborhood.

Again, sorry, I type miserably. I go back and reread posts a few days latter and end up fixing all sorts of mistakes. But that mistake was a killer to intent.

Most of the airbnb hosts I know in town just request a copy of the passport and the contact information, which is all they need. I would be interested if this guy is asking more and also interested in the method he is collecting it.

Hi Mr. E, no need to apologize for your typing mistakes--in a contest, I have full confidence that I could
win for number of mistakes. The airbnb DOES have a registration number, so that eases my mind on that score. And you and others here in the forum have assured me that asking for such info for guest registration is normal. The accommodations look nice and has good reviews. It was just the fact that there had been a hacking incident in the airbnb messaging which is supposed to be secure, so I want to be sure to whom I am sending my info (that they indeed are who they say they are). I do not yet have the exact location but it looks like it is in the area of streets Andrassy and Terez Korut. Never having been to Budapest, these streets mean nothing to me yet though I have come across many mentions of Andrassy.
Thank you for all the help you share with those of us here in the forum.

Often I can figure it out from photos in the listing. But near Andrassy u and Terez krt is a gòod choice. I'm not far away from that now at a wine tasting event at the Corinthia Hotel. About 15000 ft for all the wine you can drink. Hungary has excellent wines, but most of the vineyards are tò small for export quantities. A wine tour is always worth the time, and I know a good guide. Lovely city.

Thanks again Mr. E. You seem to be a good ambassador for Budapest!

My adopted home town.