Quick answer: If you expect to owe $1,000 or more in federal tax beyond anything withheld, you owe quarterly estimated payments. For most Florida real estate agents, setting aside 25–30% of every commission check is the right starting point. The next deadline is September 15, 2026, and it covers income you earned from June 1 through August 31. Miss it and interest starts running that day — currently 7%, compounded daily.
The safe harbor is the part worth understanding, because it’s the difference between a penalty and no penalty regardless of how your year turns out. More on that below.
I teach continuing education classes on this for agents, brokerage offices, and the Miami Realtor Association across South Florida, and estimated taxes generate more confused questions than almost anything else. Usually because nobody explained the rules — just that you’re supposed to “pay quarterly.”
The dates aren’t quarters
Start here, because the name is misleading. The four 2026 payment periods don’t divide the year evenly:
- April 15, 2026 — covers January 1 to March 31
- June 15, 2026 — covers April 1 to May 31 (two months)
- September 15, 2026 — covers June 1 to August 31 (three months)
- January 15, 2027 — covers September 1 to December 31 (four months)
None of the 2026 dates fall on a weekend or holiday, so none of them shift.
That June payment catching only two months trips people up every year. So does the last one: you can skip the January 15 payment entirely if you file your 2026 return and pay the balance by February 1, 2027.
Why agents get blindsided
Nobody withholds anything from a commission check. Your brokerage isn’t your employer for tax purposes — you get a 1099, and the entire tax bill is yours to fund.
Two things make it bigger than people expect.
Self-employment tax. On top of income tax, you owe 15.3% on your net self-employment earnings — that’s both halves of Social Security and Medicare, since you’re both employer and employee. It applies to the first $184,500 of earnings in 2026, and the 2.9% Medicare portion continues above that with no ceiling. You do get to deduct half of it, which softens the blow, but it’s the line item that surprises people most. An agent netting $120,000 owes roughly $17,000 in self-employment tax before a dollar of income tax.
Lumpy income. Three closings in March and nothing in April is a normal quarter in this business. The money arrives in bursts, gets spent on the business and the household, and the tax on it comes due on a schedule that doesn’t care when you got paid.
One piece of good news: Florida has no state income tax, so you’re only funding the federal side. Agents who move here from New York or New Jersey are used to writing two checks. You write one.
The safe harbor is the thing to actually understand
Here’s what most agents get wrong. They think the goal is estimating this year’s tax accurately. It isn’t. The goal is avoiding the penalty, and there’s a rule that lets you do that without predicting anything.
You owe no underpayment penalty if your withholding plus estimated payments equal any one of these:
- 90% of your actual 2026 tax, or
- 100% of your total 2025 tax, or
- 110% of your total 2025 tax, if your 2025 adjusted gross income was over $150,000 ($75,000 married filing separately)
That second and third option is the safe harbor, and it’s the one to use. Take last year’s total tax — the actual number off your 2025 return, not your refund or balance due — multiply by 1.0 or 1.1 depending on your AGI, divide by four. Pay that. You are protected from the penalty even if you have a monster year and end up owing far more in April.
This is what I set up for most of the agents I work with. It’s predictable, it takes ten minutes once a year, and it removes the guessing entirely. You may owe a balance at filing time, but a balance due is not a penalty.
The one time to use the 90% current-year method instead: your income dropped hard this year. Then matching last year’s higher tax means overpaying the government for twelve months at no interest.
My rule of thumb: 25–30% of every commission
For an agent who wants a number rather than a worksheet, this is where I start. When a commission hits your account, move 25% to 30% of it into a separate savings account you don’t touch. Higher end if you’re in a good year or you have other income; lower end if you’re early and your deductions are substantial.
The separate account matters more than the percentage. Money that sits in the operating account gets spent — not carelessly, just on the business, which always has something it needs. Money in an account labeled “taxes” tends to survive.
Then, when a deadline comes, pay from that account. You’re not finding the money; you already set it aside.
The penalty, and the trap inside it
The underpayment penalty is really interest. It runs at the federal short-term rate plus three points, resets quarterly, and compounds daily. It went from 6% to 7% on July 1, 2026, and gets recalculated again on October 1.
Here’s the trap. The penalty is computed separately for each period, and it runs from that period’s due date. Paying everything by April of the following year does not undo a missed September payment — interest accrued on that shortfall the entire time.
Worse: payments apply to the earliest unpaid installment first. So an agent who skipped April, then sent a payment in June thinking they were catching up, actually applied that money to April and left June open. They think they’re one quarter behind. They’re two. I see this every year, and the person is always genuinely surprised.
The W-2 spouse move
This one is worth real money and almost nobody knows it.
Withholding is treated as paid evenly across the year, no matter when it was actually withheld. Estimated payments are credited when you make them; withholding is credited as though it dripped in all year long.
So if you’re behind on estimates and your spouse has a W-2 job, increasing their withholding in October or November can retroactively cure shortfalls from April and June. A payment you make on September 15 can’t do that. Withholding can.
If you’re an agent married to someone with a regular paycheck, this is often the cleanest fix for a bad first half — and it’s why I ask about a spouse’s job before recommending anything.
If you have a PA (S-corp), this changes
If you’ve elected S-corp treatment, you’re on payroll, and your paycheck has withholding coming out of it. That withholding counts toward your obligation, evenly across the year, same as anyone else’s.
But your salary is only part of your income. The distributions aren’t withheld on, and if they’re substantial, payroll withholding alone won’t cover the bill. Two options: increase your own withholding through payroll so it covers everything, or keep making estimates on the distribution side.
I generally prefer running it all through payroll withholding — one mechanism, evenly credited, no deadlines to remember. That only works if the salary is set correctly to begin with, which is a separate conversation and the one the IRS actually examines.
When your income is genuinely uneven
If most of your production lands in the back half of the year, paying four equal installments means overpaying early. The annualized income installment method lets you pay based on what you actually earned in each period, using Form 2210 Schedule AI at filing time.
It requires clean books quarter by quarter, and it’s more work at tax time. But for a listing agent whose closings cluster in spring and summer, or someone who had a genuinely dead first quarter, it can be the difference between a penalty and none.
How to pay
IRS Direct Pay for a bank transfer with no fee, or EFTPS if you’d rather have a permanent account with payment history. Both give you a confirmation number. Keep them — when a payment goes missing, the confirmation is what resolves it.
Card payments work but carry a processing fee of roughly 2%, which on a $6,000 payment is $120 to avoid a bank transfer. Skip it.
The mistakes I see every tax season
- Paying nothing until April. The single most expensive habit in this business. Interest has been running since the previous April on money you never sent.
- Guessing at the number when last year’s return is sitting right there with a safe-harbor figure on it.
- Treating the tax savings as available cash. If it’s in the operating account, it’s gone by the deadline.
- Assuming a catch-up payment fixed an earlier miss. It applied to the oldest open quarter, not the one you meant.
- Forgetting self-employment tax entirely and setting aside based on income-tax brackets alone. That’s how a 15% set-aside becomes a five-figure surprise.
- Not adjusting after a big year. Your safe harbor is based on last year. Two strong years in a row means the second year’s payments were sized for the first.
The bottom line
Get last year’s total tax, multiply by 1.0 or 1.1, divide by four, and pay that on the four dates. That single move takes the penalty off the table and takes the guesswork with it.
The next deadline is September 15. If you haven’t paid anything yet this year, the right move isn’t to skip it because you’re already behind — it’s to pay now, because interest is compounding daily on everything outstanding and the earliest unpaid quarter is the one that’s been running longest.
While you’re at it, the deduction side matters just as much as the payment side. Every legitimate deduction you’re not taking is money you’re funding these payments with unnecessarily.
If you want help sizing your September payment, or you’ve fallen behind and want to know what it’s actually costing you, schedule a free consultation. If you’re calling about September 15, call before it.
Don Fallenbaum, M.Acc, CPA/CFF/ABV, is the Principal of Fallenbaum CPA & Advisors, LLC in Plantation, Florida. Known as “The Real Estate CPA,” he has spent 25+ years serving Realtors, real estate brokerage offices, and real estate investors, and teaches continuing education classes on entity structuring and taxes for real estate professionals.
This article is for general educational purposes and isn’t tax or legal advice for your specific situation. Talk to a qualified professional before making decisions about your estimated tax payments.