Where to register tenants for short term rentals in Istanbul?

Hi everyone,

I hope you can help.  I'm renting some flats available long-term and short-term (through Airbnb), all are in Beyoglu. I just recently realised that with the new regulations I must register my short-term tenants names/IDs with the authorities.

There's supposed to be a way to submit on-line but I can't find it, I haven't even found which authorities I'm supposed to register with. I assumed it was the Ministry of Customs and Trade but no luck so far. I've searched myself and asked a few people who should know.  They all didn't know or say 'yes we can find that out for you' but no one gets back to me with an answer. 

Does anyone know where I'm supposed to register and which authorities it is???