Pre-IPO secondary sales: the tax mechanics

Private companies stay private longer than they used to, which leaves equity holders sitting on vested options and exercised shares with no market to sell into. The pressure valve is the pre-IPO secondary: a sale of private-company shares before the initial public offering (IPO). When a window opens, it opens on someone else's schedule, at someone else's price, for a few weeks. The tax treatment of what you sell through it ranges from long-term capital gains (LTCG) to ordinary income plus payroll taxes, depending entirely on which shares leave your account. This article walks the mechanics by share type, so that when a window opens you already know which lots belong in it.

A tender is a rare liquidity window with a fixed price and a deadline. The decision the company leaves to you, which shares and how many, is a tax problem you can compute in advance.

What a pre-IPO secondary looks like

Three structures cover most of the market. A company-run tender offer: the company, or an investor it has lined up, offers to buy shares from employees and former employees at a fixed price during a fixed window, usually with a cap on how much of your vested holding you may sell, and proration if the offer is oversubscribed. A direct secondary: you sell held shares to an outside buyer, typically a fund, in a negotiated transaction that the company must approve. A structured liquidity program: a recurring, company-sponsored version of the same thing, with windows on a schedule. The legal wrappers differ; the tax analysis does not. Each one ends in a disposition of specific shares at a known price on a known date, and everything below follows from which shares those are.

Already-exercised ISO shares

Incentive stock option (ISO) shares carry two clocks from IRC §422: a sale counts as a qualifying disposition only if it happens more than two years after the grant date and more than one year after the exercise date. Miss either and the sale is a disqualifying disposition. A tender does not pause the clocks or care about them; it simply hands you a sale date, and the clocks decide what that date costs.

After both periods: LTCG, twice blessed. Sell qualifying shares into the tender and the entire gain over your strike price is long-term capital gain. If you paid alternative minimum tax (AMT) in the exercise year, the sale also cashes in the dual-basis benefit: the AMT system carries your basis at the exercise-date fair market value (FMV) rather than the strike, so the AMT system sees a much smaller gain than the regular system, and the gap releases the AMT credit you have been carrying. The Form 6251 article explains where that second basis comes from, and the credit recovery article walks the release.

Before either period: the bargain element converts. A disqualifying disposition pulls the bargain element, exercise-date FMV minus strike, into ordinary income in the year of the sale. If the tender price has fallen below the exercise-date FMV, the ordinary income is capped at your actual gain on an arm's-length sale (IRC §422(c)(2)), one of the few taxpayer-friendly corners of this rule. Anything you receive above the exercise-date FMV is capital gain, short- or long-term by the time since exercise. And because the regular system is now taxing the bargain element too, the AMT adjustment from the exercise year largely unwinds: the disposition reverses on Form 6251 and the prepaid AMT comes back as credit, on the schedule the credit recovery article describes.

Unexercised options: exercise-and-sell

Many company-run tenders let you exercise vested options and sell the shares in one step, so you never front the strike price.

For ISOs, exercise-and-sell is a disqualifying disposition in the same year as the exercise, and that changes the AMT picture entirely: when you dispose of ISO shares in the calendar year you exercised, the regular and AMT systems treat the income the same way, so no AMT adjustment arises. The spread between what you receive and your strike is ordinary income, full stop. You are trading away any shot at LTCG treatment in exchange for cash without an AMT prepayment.

For non-qualified stock options (NSOs), exercise-and-sell into a tender is taxed like any NSO exercise: the spread is ordinary wage income, subject to payroll taxes if you are an employee, with the gain measured by what you actually receive. The exercise mechanics, and the case for selling versus exercising and holding, are covered in the NSO sell-vs-hold article.

RSUs and QSBS, briefly

Most private-company restricted stock units (RSUs) are double-trigger: they vest only when both a service condition and a liquidity event (an IPO or acquisition) have occurred. Before the IPO the second trigger has not fired, you hold no shares, and there is nothing to tender. Some companies amend awards or settle a portion in connection with a tender; if yours does, the settled value is ordinary income like any RSU vest. For most equity holders the answer is simply that RSUs sit this one out.

If your shares might be qualified small business stock (QSBS), check the clock before you tender. The IRC §1202 exclusion generally requires a five-year holding period (stock acquired after July 4, 2025 earns partial exclusions at three and four years), and a secondary sale before the mark forfeits the exclusion that waiting would have earned, though a §1045 rollover can keep the clock running. Shares that do qualify get the exclusion in a tender the same as in any sale. The QSBS article covers the qualification tests and the cap math.

The tender price and the 409A value

Private companies carry an appraised FMV, the 409A valuation, used to price option grants. Tender offers are often struck at a premium to it, closer to what investors last paid. For taxes, what matters in an exercise-and-sell is what you actually receive: a tender at a premium to the 409A value widens the spread that gets taxed as ordinary income. The premium is real money, but it arrives pre-taxed at your highest rates. One second-order effect to know about: a tender can be an input to the company's next 409A valuation, which bears on the strike price of future grants and the bargain element of future exercises.

Withholding and the cash-flow gap

Where the cash for the tax bill comes from depends, again, on share type. NSO exercises in a company-run tender are withheld like payroll: federal withholding at the flat supplemental rate, currently 22% (37% on supplemental wages above $1 million), plus state and payroll taxes. If your marginal rate is above the supplemental rate, the withholding under-collects and the difference is due at filing, the same trap the RSU withholding gap article prices for vests. ISO disqualifying dispositions are stranger: the ordinary income lands on your W-2, but the statute requires no income tax withholding on it (IRC §421(b)) and exempts it from payroll taxes (IRC §3121(a)(22)), so nothing is collected at all. A direct secondary of shares you already hold has no withholding either; it is a stock sale, and the buyer is not your employer. In both of those cases the entire tax bill rides on you: an estimated payment in the quarter of the sale, or a prior-year safe harbor, keeps the underpayment penalty off the top.

The planning angle: which lots, how many

Because the window is rare and the price is fixed, the whole decision is lot selection: which shares, with which basis, holding period, and share type, and how many of them. That is an after-tax computation, not a judgment call. If you are raising a target amount, the Equity Funding Plan Calculator runs it directly: give it your lots (shares, cost basis, acquisition dates), the tender price (prices are explicit inputs, so a private company works the same as a public one), and your after-tax target, and it picks the lots and timing, classifies each sale as short- or long-term on its sale date, and itemizes federal, state, and net investment income tax per sale.

For unexercised ISOs the question is sharper: exercise-and-sell into the tender for ordinary-taxed cash now, or exercise-and-hold toward a qualifying disposition later. The AMT + ISO Exercise Calculator prices the second branch, the one you would be choosing against: the AMT cost of exercising and holding those options, the most you could exercise this year before AMT starts, and the multi-year schedule that spreads the rest. It also handles the departed-employee case, where a 90-day post-termination exercise window turns the tender from an opportunity into a deadline.

This article covers the federal mechanics; the tender's own paperwork, state treatment, and transfer approvals belong to your tax adviser and the company's equity team.

Where to go from here

If you exercised ISOs and are weighing a sale against the clocks, the Form 6251 article shows what the exercise already cost and the credit recovery article shows what a sale gives back. If the tender is funding a specific goal, the funding a goal article covers the schedule math, and after the IPO the same selling problem returns wearing a 10b5-1 plan.

The calculators handle one decision at a time. OptionsAhoy plans the full picture jointly: every ISO, NSO, RSU vest, concentrated position, and hedge, across bullish, neutral, and bearish scenarios, with the AMT computation and credit timing built into the schedule. The output is a year-by-year Plan optimized for total after-tax wealth. Free during beta.