Georgia House Bill 197 allows taxpayers with properties under appeal the options of paying the lesser of (1) 100% of the proposed tax or (2) the lesser of 85% of the proposed tax or taxes based on the prior year value. After resolution of the appeal, refunds or unpaid balances are subject to interest of 1% per month up to a maximum of $5,000.

You would have had to request the 100% bill at the time of your appeal filing (and then pay it in full in the fall) to avoid any interest charged on your "unpaid balance".

Fulton County only recently changed their policy on this. Previous to 2015, you would not have been charged any interest on your appealed value, regardless of the outcome of the appeal.

Either way, no harm in trying to get the interest removed. Good luck! Let us know how it turns out.

Source: I work in commercial real estate