The appeal itself is not complicated. The trap is filing it the wrong way, missing the 45-day clock, or ignoring the amended value notice.

Every spring, thousands of Gwinnett County homeowners receive an Annual Notice of Assessment.

It is easy to mistake it for another piece of county paperwork.

But this notice is one of the most important tax documents a homeowner gets all year. It is not the tax bill. It is the county’s statement of what it thinks your property is worth — and that value helps determine the tax bill that comes later.

The important part is what comes next.

If you disagree with the value, you usually have 45 days from the date in the upper-right corner of the assessment notice to appeal. Gwinnett says appeals must be filed electronically or postmarked within that 45-day period.

That deadline is where many homeowners lose before they even start.

The first rule: do not email or fax the appeal

One of the more interesting Gwinnett-specific rules is not about home values at all.

It is about how the appeal is filed.

Gwinnett’s Board of Assessors adopted a written filing policy on October 1, 2025. The policy says appeals are accepted through the Assessors’ Office online portal, by mail, or in person. It also says the office does not accept appeals by email or fax.

That is easy to overlook.

A homeowner could write a perfectly good appeal, attach photos, explain why the property is overvalued, email it to the county, and still not have properly filed the appeal.

For Gwinnett, the safer options are simple: use the online portal, mail the appeal with tracking, or hand-deliver it to the Assessors’ Office.

The second rule: starting online is not the same as filing

Gwinnett’s filing policy also makes another point clear: an online appeal has to be completed by the deadline.

The county says the property owner or agent has until 11:59 p.m. Eastern Time on the appeal deadline shown on the notice to complete the appeal.

If an online appeal is started but not completed by the deadline, Gwinnett says it will not be treated as timely filed. The policy also says there are no extensions, continuances, or special circumstances for late filing.

That is the kind of local rule that can cost a homeowner money.

Not because the case was weak. Because the submission was incomplete.

What can you actually use to file?

Gwinnett gives homeowners a few practical tools.

You can file through the county’s online appeal system. You can also mail or deliver a completed PT-311A appeal form.

Gwinnett also says it can accept a letter of disagreement as a formal appeal if it identifies the property by parcel number or address and is received or postmarked within the 45-day window.

That last part is useful. It means the first step is not writing a legal brief. The first step is preserving your right to appeal before the clock runs out.

The county lists three basic grounds for appeal:

  • Value. Would the property sell for the amount Gwinnett assigned?
  • Taxability. Should the property be taxable?
  • Uniformity. Is the property assessed consistently with similar properties?

For most homeowners, the strongest arguments are usually value and uniformity. Value means the fair market value is too high. Uniformity means similar homes are being treated more favorably.

What happens after you file?

After Gwinnett receives the appeal, appraisal staff reviews it.

The appraiser may accept the owner’s proposed value, choose a new value, or decide no change is needed.

If the county proposes a new value, the homeowner receives an Amended Notice of Assessment. At that point, the owner can accept or reject the amended value.

Gwinnett says the owner has 30 days from the amended notice to reject it and continue the appeal. If no action is taken within that 30-day period, the value defaults to the amended notice value.

This is another place homeowners can accidentally give up leverage. Getting a lower amended value may be good. But it may not be enough.

If the county reduces a home from $500,000 to $475,000, but the evidence supports $430,000, the homeowner needs to reject the amended value on time to keep going.

If no adjustment is made, or if the owner rejects the amended value, the appeal can move to the next level. The Clerk of Courts notifies the taxpayer of a Board of Equalization hearing, where the homeowner and county appraiser can present evidence.

The notice changed, too

There is one more reason Gwinnett homeowners should read the notice carefully.

Gwinnett says recent Georgia legislation created a new standardized statewide assessment notice for 2025. Because of House Bill 92, the notice format was changed, and each city, county, and school system must estimate a rollback millage rate.

Gwinnett says estimated taxes are no longer shown unless a jurisdiction did not provide its estimate.

In plain English: the notice may look different, and it may not show taxes the way homeowners expect. But the appeal clock still matters.

The takeaway for Gwinnett homeowners

A Gwinnett County property tax appeal is not just about proving the county’s value is wrong.

It is also about using the right filing method, completing the online appeal before the deadline, responding to any amended value within 30 days, and knowing whether your argument is based on value, taxability, or uniformity.

The tax bill comes later. The appeal deadline comes first.

For homeowners who do not want to handle the research, filing, or hearing process alone, LowerTheTax.com helps review assessment notices, compare nearby sales, check county records, and prepare property tax appeals.

In Gwinnett County, that process starts with one simple step: do not ignore the notice.