Two buyers each fall in love with a house in Alpharetta this month. Both homes list in the mid-$600,000s. Both carry an Alpharetta address and sit five minutes from GA-400, ten minutes from Avalon. On paper, from a portal search, they look like the same market.
They are not. One buyer's kids will attend Alpharetta High School. The other's will attend a Forsyth County school an hour before the first family's household ever thinks about it, because the property lines that decide school assignment, tax exemptions, and how fast a tax bill grows over time run straight between homes that share an Alpharetta address, and neither the listing photos nor the median price on any portal will tell you which side you're standing on.
Homes with an Alpharetta address are split across two counties, Fulton and Forsyth. That split isn't a footnote. It changes which school district your address falls into, what homestead exemption applies to your tax bill, and how quickly your assessed value is allowed to climb after closing. And the data on how it plays out is the kind of thing that runs backward from what most buyers expect.
Same Address, Two Governments
The Fulton portion of Alpharetta is served by Fulton County Schools, home to Alpharetta High School. Alpharetta addresses on the Forsyth side fall under the separate Forsyth County School District, headquartered in Cumming. These aren't feeder patterns within one system. They're two different school boards, two different calendars, two different enrollment offices.
Property tax administration splits the same way. Fulton County's Board of Assessors handles valuations and homestead applications for the Fulton side, with an office at 11575 Maxwell Road in Alpharetta. Forsyth County runs its own separate assessment calendar. A homebuyer signing a contract on one side of the county line is, procedurally, dealing with an entirely different local government than a buyer signing three streets over.
The Tax Gap That Runs Backward
Here's where it gets interesting for anyone comparing two listings side by side. Ownwell's property tax data for Alpharetta, broken out by county, shows the Forsyth side carrying a median home price around $587,630 with a median tax bill near $4,794. The Fulton side shows a median home price around $662,300, higher, with a median tax bill near $1,417.
Read that again. The more expensive side of the line has the smaller tax bill.
| Forsyth-side Alpharetta | Fulton-side Alpharetta | |
|---|---|---|
| Median home price | ~$587,630 | ~$662,300 |
| Median annual tax bill | ~$4,794 | ~$1,417 |
The gap isn't mostly about millage rates. Exemptions and assessment rules differ by county. On top of that, Appen Media reported that Alpharetta, along with Roswell and Milton, created a local floating homestead exemption back in 2018.
"adjusted annually at the lesser of 3 percent or CPI"
That's how Alpharetta's finance director described the cap when the exemption was created. Fulton County announced that it opted into the floating homestead exemption authorized by HB 581 for the 2025 tax year. Forsyth County was still weighing that decision as of early 2025, with staff recommending the county not opt out
Where the Line Actually Crosses a Street
This isn't an abstraction confined to zip code maps. Drive west on Union Hill Road off GA-400's Exit 12 and turn into the Chadbourne subdivision, and you cross from Fulton into Forsyth mid-street. Neighbors two driveways apart can be filing homestead paperwork with different counties, sending their kids to different school systems, and watching their tax bills grow on different timelines, all while receiving mail addressed to the same city.
For a buyer working from a portal's map view, that distinction is invisible until it isn't.
What to Check Before You Get Attached to a House
- Ask which county the specific parcel sits in. Not the city, the county. An Alpharetta address alone doesn't answer it.
- Confirm the school assignment directly with the relevant district rather than assuming based on the city name.
- Ask what homestead exemption currently applies to the property.
- Factor the tax trajectory into your offer math, not just the first year's bill. A lower sticker price on the Forsyth side can carry a materially higher long-term carrying cost, and a higher sticker price on the Fulton side can carry a lower one.
The Appeal Calendars Don't Match Either
The two counties don't even run their assessment cycles on the same schedule. Forsyth County typically mails assessment notices in spring, reaching most mailboxes by mid-May, with an appeal window. Fulton County mails notices in June, with an appeal deadline. A homeowner who buys expecting one calendar and gets the other can miss a window entirely, and that pattern repeats every year on roughly the same timing.
FAQ
How do I find out which county a specific Alpharetta address is in? The property's county appears on the tax record itself, searchable through the Fulton County Tax Commissioner's site for Fulton parcels or the Forsyth County Tax Commissioner for Forsyth parcels. Your closing attorney will also confirm this before closing, but it's worth knowing before you write an offer, not after.
Does the county line affect resale value? The research here doesn't support a claim either way on resale value specifically. What it does show clearly is that carrying costs differ, and carrying costs are part of what a future buyer will weigh too.
Comparing two listings that both say "Alpharetta" isn't as simple as comparing square footage and asking price. The county line changes the school your kids attend, the exemption paperwork you file, and the multi-year shape of your tax bill, and none of that shows up in a portal's summary card.
If you're weighing a purchase on either side of that line, or trying to model what a specific address will actually cost you five years out, Tina Sui and the TJS Team can walk through the county-specific numbers with you in English or Mandarin, whether you're buying your first home in Alpharetta or building a long-term portfolio around it.
