Miami is weird. You’ve got palm trees, neon lights, and some of the most confusing property tax bills in the entire country. If you’re looking at a $2 million condo in Brickell or a ranch-style house in Kendall, the number on the listing site is probably a lie. Seriously. The tax estimate you see on Zillow or Redfin is almost always based on what the current owner pays, not what you will pay. That’s a massive trap.
Florida has these specific laws—the Save Our Homes act and the portability rules—that create a huge gap between long-time residents and new buyers. It’s basically a tale of two cities. One person pays $4,000 a year because they bought in 1998, while their next-door neighbor pays $18,000 for the exact same floor plan. It feels unfair. It kind of is. But if you don't understand how the Miami-Dade Property Appraiser calculates your "ad valorem" tax, you're going to have a very bad time at the closing table.
The Sticker Shock: Why Miami Real Estate Taxes Reset
When a property changes hands in Miami, the "Save Our Homes" (SOH) cap vanishes. This is the most important thing to realize. Under Florida law, the assessed value of a primary residence can’t grow by more than 3% per year (or the Consumer Price Index, whichever is lower). Over twenty years of Miami’s insane appreciation, that cap creates a massive shield.
But the moment you buy that house? Boom.
💡 You might also like: Converting 285 GBP to USD: Why the Rate You See Online Isn't What You Get
The shield shatters. The Miami-Dade Property Appraiser, currently led by Pedro J. Garcia, resets the assessed value to the current market value. This is called the "reset." If the previous owner was a grandma who lived there since the 80s, her assessed value might be $200,000 while the market value is $900,000. You buy it for $900,000, and suddenly your tax bill isn't based on her tiny number anymore. It's based on yours. You might see your tax bill triple in the first year. People cry at their mailboxes. It happens every day in Coral Gables and Pinecrest.
The Millage Rate Maze
You’ll hear the term "millage rate" thrown around by brokers. It sounds technical. It’s just a fancy way of saying "dollars per $1,000 of value."
In Miami-Dade, your total tax rate is a mashup of several different taxing authorities. You’ve got the countywide tax, the school board tax (which is usually a huge chunk), and then your specific city tax. If you live in an unincorporated part of the county, you pay a "UMSA" (Unincorporated Municipal Service Area) tax instead of a city tax.
Miami’s average millage rate usually hovers around 17 to 20 mills. To do the quick math: if your house is assessed at $500,000 and the rate is 18 mills, you're looking at $9,000.
$500,000 / 1,000 = 500.
500 * 18 = $9,000.
👉 See also: The Certificate of Good Standing Tennessee Strategy: Why Businesses Actually Need It
But wait. Don't forget the non-ad valorem assessments. These are flat fees for things like trash collection, lighting districts, or cleaning up Biscayne Bay. These show up on your bill regardless of what your house is worth. In some parts of Miami, the trash fee alone is several hundred dollars.
Homestead Exemption: Your Only Real Defense
You’ve got to file for Homestead. If you don't, you're essentially donating money to the government. If the home is your permanent residence, you get a $50,000 exemption. The first $25,000 applies to all taxes. The second $25,000 applies to everything except school board taxes.
More importantly, the Homestead Exemption triggers that 3% cap I mentioned earlier. Even if Miami real estate prices go up 20% in a single year—which they definitely have recently—your tax assessment stays locked in a slow crawl.
There are other "kickers" too. Are you a senior with limited income? There’s an extra exemption for that. Are you a veteran with a disability? You might get a massive break. There’s even a "Granny Flat" exemption if you’re building a suite for a parent. But the county won't just give these to you. You have to go to the South Dade Government Center or the downtown office and prove you deserve them. You have to apply by March 1st of the year you want the exemption to start. If you miss that date, you’re out of luck until next year. No exceptions.
Portability: Moving Your Tax Savings
This is a uniquely Florida thing. Let’s say you’ve lived in a house in Kendall for ten years. You have $100,000 in "Save Our Homes" savings (the difference between what your house is worth and what you’re actually taxed on). If you move to a new house in Miami Beach, you can "port" that $100,000 discount to the new property.
It’s called the Transfer of Homestead Assessment Difference.
It makes moving less painful. Without portability, a lot of people would be "house-locked," unable to sell because they couldn't afford the taxes on a new place. You have three years from the time you sell your old place to use this benefit. Honestly, it's one of the few ways the system actually helps locals stay in the area as prices skyrocket.
💡 You might also like: Why Core Values Actually Matter (And Why Most Companies Get Them Wrong)
The Non-Resident Tax Trap
If you're buying a second home or an investment property in Miami, prepare to pay full freight. There is no 3% cap for you. Instead, there is a 10% cap for non-homestead properties. While 10% sounds okay, it’s a lot higher than 3%. Over a decade, an investor’s tax bill will balloon much faster than a neighbor’s who actually lives in their house. This is why rent in Miami is so expensive; landlords are just passing these massive tax hikes down to the tenants.
TRIM Notices: Your Chance to Fight Back
Every August, the mailman drops off a blue-and-white form called the TRIM (Truth in Millage) notice. Most people throw it in the trash. Don't do that. This isn't your bill; it's an estimate of what your bill will be in November.
This is your window to complain.
If the appraiser says your condo is worth $800,000 but the identical unit downstairs just sold for $700,000, you have a case. You can file a petition with the Value Adjustment Board (VAB).
You’ve got to be prepared, though. You can't just say "taxes are too high." Everyone thinks that. You need data. You need "comps"—comparable sales—that show the county’s math is wrong. There are professional tax appeal firms in Miami that do this for a living. They usually take a percentage of what they save you. If you’re a high-net-worth owner in Indian Creek or Star Island, you almost certainly have a lawyer fighting your TRIM notice every single year. For a regular homeowner, it’s often worth doing yourself if the gap is big enough.
How to Estimate Your Future Taxes
If you are buying a home right now, ignore the "Current Taxes" line on the flyer. Instead, do this:
- Look at the purchase price.
- Multiply it by 0.8 (the county usually assesses at about 80% of market value, though they're getting more aggressive).
- Apply the millage rate for that specific zip code (usually around 1.8% to 2%).
So, on a $1,000,000 home, expect an assessment around $800,000. At a 1.9% tax rate, your bill will be roughly $15,200. If the seller was paying $6,000, don't get used to that number. Your escrow payment will jump significantly in your second year of ownership, which can lead to a "shortage" and a massive spike in your monthly mortgage payment. I've seen people's monthly payments go up by $800 overnight because they didn't budget for the tax reset.
Specific Miami Real Estate Tax Actions
Verify the current exemptions. Go to the Miami-Dade Property Appraiser's website. Type in the address of the house you want to buy. Look at the "Taxable Value" versus the "Just Value." If the Just Value is way higher than the Taxable Value, you are looking at a huge tax hike the year after you buy.
Calculate the "New Owner" estimate. Use the tax estimator tool on the county website. It’s actually pretty decent. It allows you to plug in a projected purchase price and see what the bill looks like without the previous owner’s protections.
File your Homestead paperwork immediately. Once you have the deed and you've moved in, get your Florida driver's license updated to that address. You'll need it to apply for the exemption. Don't wait until the March deadline; do it the week you move in.
Review your TRIM notice in August. Set a calendar reminder. If your assessment looks insane, you only have a few weeks to file an appeal. If you miss the window, you’re stuck with that bill for the year.
Check for back taxes. During your title search, make sure there are no outstanding tax certificates on the property. In Florida, if you don't pay your taxes, the county sells "certificates" to investors who pay the bill for you in exchange for a high interest rate. If those aren't cleared at closing, you’re buying someone else’s debt.