What the TRIM Notice Is
TRIM stands for Truth in Millage. Every Florida county property appraiser mails one to every property owner in mid to late August. It is formally a "Notice of Proposed Property Taxes", it says DO NOT PAY somewhere near the top, and it is the single most important piece of property tax mail you get all year.
The reason is timing. By the time the actual bill lands on November 1, the values are settled and the rates are adopted. The TRIM notice arrives while both are still open — while you can still challenge a value, fix a missing exemption, or turn up at a budget hearing about a proposed rate increase. Miss the window it opens and your only remaining option is to pay and try again next year.
Reading It, Line by Line
The layout varies slightly by county but the substance is set by statute. You are looking at three columns of numbers for each taxing authority:
| Column | What it means |
|---|---|
| Last year's actual | What you were actually taxed last year. Your baseline. |
| This year, if no budget change | What you would pay if each authority kept its budget flat. This isolates the effect of your value going up. |
| This year, as proposed | What you will pay under the budgets actually proposed. The difference against the middle column is the effect of rate decisions. |
That middle column is the one nobody reads and the one that answers the question everybody asks. If the middle column is much higher than last year, your assessment rose. If the right column is much higher than the middle one, a taxing authority is raising your rate. The two problems have completely different remedies, which is the whole point of printing them separately. Our guide to why property tax bills go up covers the distinction in general terms.
Above that table you will find your valuation lines:
- Just (market) value — what the appraiser thinks the property would sell for as of January 1.
- Assessed value — just value reduced by the Save Our Homes cap if you are homesteaded, or the 10% non-homestead cap if you are not.
- Exemptions — each one itemised.
- Taxable value — what the millage is actually applied to.
The notice also lists the date, time and place of each taxing authority's public budget hearing. Those hearings are where rates are set, they are open, and they are very thinly attended.
The Three Things to Check
- Are your exemptions on it? Look for the homestead exemption line, and any additional veteran, senior, widow or disability exemptions you claimed. A missing exemption is the easiest error to get fixed and the most costly to ignore. If you moved within Florida, confirm the transferred Save Our Homes amount appears — see portability.
- Is the just value defensible? Not "is it high" — is it higher than what your house would actually have sold for on January 1? If comparable homes nearby sold for meaningfully less, you have something to work with. Finding comparables that hold up explains what counts as evidence.
- Are the property details right? Square footage, bedroom count, year built, pool, acreage. Appraisers work from records that are sometimes decades stale. A clerical error in your favour is rare; one against you is common and simple to correct.
The 25-Day Clock
To challenge anything on the notice you file a petition with your county's Value Adjustment Board, and the deadline is 25 days after the TRIM notice is mailed. The exact date is printed on the notice itself. Do not calculate it from the day it reached you, and do not assume it matches a neighbouring county — mailing dates differ.
In practice this falls in mid-September across most of Florida. The filing fee is modest, typically around $15 per parcel. You can petition over a value you dispute, an exemption that was denied or omitted, a portability transfer that was not applied, or a classification issue.
After filing you get a hearing before a special magistrate, usually months later, often into the following year. That timing is normal and does not mean anything has gone wrong.
Try the Informal Route First — But Watch the Date
Every property appraiser's office will discuss your value informally, and a genuine factual error (wrong square footage, an exemption they overlooked) is frequently fixed in one phone call without a petition at all. It is worth the call.
The trap: an informal conversation does not extend the 25-day deadline. Offices get busy in September, calls do not get returned, and people discover in October that the window shut while they were waiting. If your deadline is close, file the petition first and withdraw it if the informal route succeeds. The fee is small; the lost year is not.
What Happens Next
The actual bill is mailed by the tax collector on November 1. Florida rewards paying early, on a sliding scale:
| Pay in | Discount |
|---|---|
| November | 4% |
| December | 3% |
| January | 2% |
| February | 1% |
| March | None — due by March 31 |
Taxes become delinquent on April 1, and Florida moves to a tax certificate sale from there, which is a genuinely serious process — see what happens if you do not pay.
If your taxes are paid through a mortgage escrow account, you get the TRIM notice but your lender gets the bill. You still need to read the notice, because an escrow account does not check whether your exemptions are right — it just pays whatever is billed, and then raises your monthly payment to match. See how property tax escrow works.
Which Challenges Actually Work
Ranked roughly by how often they succeed:
- A missing or denied exemption you were clearly entitled to. Documentary, objective, usually fixed.
- A factual error in the property record. Also documentary. Bring the survey, the plans, photographs.
- A portability transfer not applied. Common after a move, and straightforward once both counties confirm the figures.
- An over-stated just value. Winnable, but only with genuine comparable sales from around January 1. "My neighbour pays less" is not an argument — under Save Our Homes, two identical houses paying very different taxes is the system working as designed, not evidence of error.
Related guides: Miami-Dade property tax by city.
Bottom Line
When the TRIM notice arrives in August, open it the same week. Check that your exemptions are listed, that the property details are right, and that the just value is one you could defend against real sales. If any of the three is wrong, note the petition deadline printed on the notice — 25 days from mailing, typically mid-September — and act inside it. Calling the appraiser is worth doing, but do not let the call run out the clock.
Not yet homesteaded? That is a March 1 job, and it is the bigger saving: see the Florida homestead exemption guide.
General information, not legal or tax advice. Petition deadlines, fees and procedures are set county by county — the date printed on your own TRIM notice governs.