Property tax

Just take your last invoice with you to one of the property tax offices and they will pull up arrears and current owings

What if she has no invoice? What is the procedure then and where does she go to make this payment for the taxes?
Regards Steve.

Just go to the local council and give them your name and address, if they can't help they'll send you to the right place.

Is there any way of paying your property tax on line ? Or do you have to go to the office in the area that your house is and pay it that way?

You can pay the property tax online. I suggest you to look the website of the municipality for the IBAN. But you have to be careful for the reason for payment and the code for each tax.

I pay my Plovdiv taxes online, but it's a big city with a decent website. I don't know if everywhere in Bulgaria is as up to date.

Also, it needed a password/PIN to be issued, which required me to visit the office in person with my ID first. So if you're not in Bulgaria, this is probably a problem.

Epay.bg also has property tax payments, but you need your ID number and the "batch number". I'd guess this works if you have an invoice already. Otherwise, also a problem.

Separately, until I figured it out, I was very tardy both registering my property, and paying the taxes. There is a fine for late registration and late payment, but it wasn't very big. So, hopefully, it won't be too painful if you sort it out when you manage to get over here.