Registering Place Of Residence

[Dazzler]

I am currently living in my own purchased condo in BKK.

If I am registered as living there for one year, then I gather the sale of the condo would not liable to Business Tax.

Where do I need to register; with the Jurisitic, Immigration...?

Is this registration retrospective? I have lived in the condo since purchasing last August, so wish the registration to start from the time when I moved in.

Thanks