An installment sale of a business lets you pay tax on the gain as payments arrive; Apollon Wealth Management treats it as a timing tool that saves money only when it lowers your bracket. On a $400,000 sale of shares with a $4,000 basis, 99 percent of every principal dollar is taxable gain, so a $36,000 annual payment puts $35,640 of gain on that year's Form 6252. The tax is only half the decision. The other half is whether the buyer keeps paying for ten years. Owners raise this in first meetings with Apollon Wealth Management, and we'll follow one hypothetical couple through it.
By Marcus Thompson, CFA — Wealth Manager | Reviewed by Hiroshi Tanaka, CFPMarcus builds diversified portfolios for high-net-worth clients, with deep expertise in asset allocation and risk management.
A note only saves tax when it keeps a year under a line you'd otherwise cross. If it doesn't, you're buying time, not savings.
CPA and Tax Director, Apollon Wealth Management
I'd rather see 10 percent down and the shares in escrow than a higher price on an unsecured note.
CFP® and Lead Advisor, Apollon Wealth Management
When your buyer has $40,000 and you want $400,000
Raj and Sharon, a hypothetical couple aged 47 and 45 with three children under 15, own an IT managed-services firm worth about $4 million. Raj's 50/50 partner wants out within two years. That $2 million buyout is a separate decision (the buy-sell agreement funding page covers it). Today the question is smaller: Raj wants his service manager to buy 10 percent, about $400,000, and she has roughly $40,000 saved. A ten-year seller note is the only way the deal happens.
People paraphrase the rule as 'you only pay tax when you get paid.' The official rule is narrower. Under Section 453, the gross profit percentage of each principal payment is taxed in the year it arrives and reported on Form 6252, the IRS form for installment sales. Interest on the note is ordinary income every year. Depreciation recapture in an asset sale is taxed in full in the year of sale, and inventory and publicly traded stock can't use the method at all. The total gain does not shrink.
One more rule matters for owners selling to a child. If the buyer is a related person who resells within two years, the IRS generally treats the seller as receiving the resale proceeds, limited to the contract price minus payments already received. Raj's buyer is an unrelated employee, so this rule stays out of his way. It would not if he were selling to a son or daughter.
How much tax lands each year on a ten-year note?
On Raj's note, $39,600 of long-term gain lands on the return in year one and $35,640 in each of the next ten years, plus ordinary-income interest. Over the note that adds up to $396,000, the same total gain a lump sum would put on a single return. Spreading changes when the tax cost arrives, not how large the gain is.
A hypothetical household makes the arithmetic easy to check. Raj and Sharon sell 10 percent of his S corporation shares for $400,000. His basis is $4,000, so gross profit is $396,000 and the gross profit percentage is 99 percent ($396,000 ÷ $400,000). The buyer pays $40,000 at closing, then $36,000 of principal a year for ten years ($40,000 + $360,000 = $400,000). Year one: $40,000 × 0.99 = $39,600. Each later year: $36,000 × 0.99 = $35,640. Total: $39,600 + 10 × $35,640 = $396,000. Our calculator runs the same math with your own price and basis.
The gain is long-term capital gain, since Raj has held the shares well over a year. The interest is ordinary income. Both count toward the 3.8 percent net investment income tax, which starts at $250,000 of modified adjusted gross income for a married couple filing jointly. Raj's wages already put them over that line, so the surtax applies either way.
So is Raj saving or only shifting? Mostly shifting. Their other income keeps the gain in the same capital gains bracket in a lump-sum year or a spread year. Spreading saves real money only when a lump sum would push gain into a higher bracket (check the current IRS brackets) or over a threshold the spread years stay under. And the note's value depends on the buyer's business doing well; payments are never certain.
Before Apollon Wealth Management suggests note terms, it projects each year's Form 6252 gain and interest next to the couple's expected wages. Then the decisions go on a short list in deadline order. The interest rate is locked when the note is signed, using that month's published federal rate. The choice to elect out of the installment method must be made on the sale-year return, filed by its due date including extensions.
The numbers year by year
Saving versus shifting
Decision rule: if spreading the gain would not keep any year under a line you'd otherwise cross (a higher capital gains bracket, the $250,000 joint net investment income tax line, or a Medicare premium tier within two years of enrolling), the installment method only delays the tax. Accept a note for the buyer's sake and protect yourself with down payment, interest and collateral.
What age turns a timing tool into real savings?
Take a second hypothetical seller, a 63-year-old owner with little income after leaving the company. A lump sum could push income past the $218,000 joint line where the 2026 Medicare Part B premium rises from $202.90 to $284.10 a month (premiums are set from income two years earlier), and past the $250,000 net investment income tax line.
Spread over ten years, the same gain can stay under both lines. She should usually take the note, while Raj, at 47 with high wages, gains mostly time.
If Sharon asks what happens when the payments stop
The spouse who isn't running the firm usually raises the default question first. Sharon's version: with three children under 15 and college ahead, what do we have if she quits in year four? Sit down with the eleven-year payment schedule printed out and mark the years the family needs the cash. That page tells you how much of the note you can afford to lose.
Raj set his terms before agreeing. First, at least 10 percent down. Then an interest rate no lower than the applicable federal rate published for the signing month, which is the IRS minimum for seller notes. Next, the shares pledged as collateral and held in escrow until the note is paid. After that, an acceleration clause if she misses two payments or leaves the company. Last, a personal guarantee and term life insurance on the buyer that pays the note holder.
Most of these items live with the CPA, not the attorney: basis, deal structure and the interest rate all decide the tax cost.
A zero-interest note written as a favor to a loyal employee looks free at closing, but it isn't. From the first payment, the IRS treats part of each principal payment as interest. A slice of Raj's $396,000 gain moves from capital gains rates to ordinary rates every year of the note. The gross profit numbers on each Form 6252 have to reflect the smaller principal from the start.
Two limits apply. The installment method does nothing to raise cash for the partner buyout. And if the firm is an LLC taxed as a partnership, gain tied to receivables and other ordinary-income items can't be spread over the note at all.
Talking it through at home
Terms to require
| Item | Why it matters | Where to find it |
|---|---|---|
| Your basis in the shares | Sets the gross profit percentage | Form 7203, CPA basis schedule |
| Stock or asset sale | Asset sales tax recapture in year one | Letter of intent, purchase agreement |
| Applicable federal rate | Below it, principal becomes interest | IRS monthly AFR ruling |
| Buyer's finances | Sizes the default risk | Personal financial statement, credit report |
| Collateral and escrow | What you can take back | Pledge agreement, stock ledger |
| Your other income | Which bracket each year's gain hits | Latest Form 1040, pay records |
Talking to Apollon Wealth Management once a buyer asks for terms
Call Apollon Wealth Management when a buyer asks you to carry part of the price, before any term sheet is signed, because the interest rate and down payment get set at signing. Bring the draft term sheet, the S corporation basis worksheet (Form 7203 or your CPA's basis schedule) with recent K-1s, your latest Form 1040, and the buyer's personal financial statement.
A note only saves tax when it keeps a year under a line you'd otherwise cross; otherwise it buys you time.
Your questions about an installment sale of a business, answered
By what date do I have to decide whether to report the whole gain in the year of sale?
The installment method applies automatically, so the decision is whether to elect out of it. That election is due with your tax return for the year of sale, including extensions. Once made, it generally can't be reversed without IRS consent, so project both paths before filing.
Can I sell the note or borrow against it later if we need the cash sooner?
Yes, but selling the note usually triggers the remaining deferred gain in that year, and buyers of notes pay a discount, especially for unsecured notes from small businesses. Borrowing against a note can also trigger tax rules. Talk to your CPA before pledging it.
Will the yearly note payments show up when our kids apply for college financial aid?
Yes. The taxable gain and interest appear as income on your return, and aid formulas generally read that income. A lump-sum sale would show all of it in one year, which could hurt one aid year badly. Spreading gain can smooth it, but check each school's rules.
How big should the down payment be when selling shares to an employee on a note?
A common floor is 10 percent, which is what Raj required in this example. A larger down payment cuts your default risk because you hold cash you can't lose. A buyer with $40,000 on a $400,000 price sits right at that floor.
Does an installment sale reduce the total capital gains tax or only spread it out?
Usually it only spreads it out. Total gain stays the same. It saves money when spreading keeps you under a higher capital gains bracket, the 3.8 percent net investment income tax line, or a Medicare premium tier you'd cross with a lump sum.
What interest rate does the IRS require on a seller-financed business note?
The note should charge at least the applicable federal rate for the month of signing, which the IRS publishes monthly. Charge less and the IRS treats part of each principal payment as interest, turning some capital gain into ordinary income. Check the current published rate.
Read the rules at the source
This content is general information only and does not constitute investment, tax or legal advice tailored to your circumstances. Investing involves risk, including possible loss of principal. Past performance is no guarantee of future results. Consult a qualified professional before making any financial or legal decision.