Your company just announced a tender offer, and the number next to your vested shares suddenly looks life-changing. Here is the part nobody puts in the announcement email: the check you receive is not the amount you keep, the tax bill can arrive with zero withholding taken out, and the decision you make in a three-week election window can cost or save you tens of thousands of dollars depending on what kind of equity you hold.
Tender offers have become the standard way maturing private companies give employees liquidity before an IPO or acquisition. Companies are staying private longer — sometimes a decade — and workers with years of vested equity understandably grow tired of paper wealth they cannot spend. A well-run tender offer lets you sell a slice of your holdings, often 10 to 20 percent of your vested shares, while the company stays private. But unlike selling public stock with a broker that withholds and reports everything neatly, a private-company sale puts most of the tax and planning burden on you.
This guide walks through how tender offers work, how the taxes differ for ISOs, NSOs, and RSUs, and the mistakes that most often blindside first-time sellers.
How a Tender Offer Actually Works
A tender offer is a secondary transaction: instead of the company issuing new shares to raise money, existing shareholders — employees, former employees, sometimes early investors — sell shares they already hold. The buyer is typically a late-stage investor, a secondary fund, or the company itself buying shares back. The company sets the price, usually at its current 409A valuation or the price of its most recent funding round, sometimes with a small discount.
The mechanics follow a predictable sequence:
- Announcement and disclosures. The company notifies eligible holders and shares an offer memo with the price per share, maximum purchase amount, eligibility rules, and financial disclosures. Eligibility frequently differs for current employees, former employees, and outside investors, so read the fine print about which of your holdings qualify.
- Election window. You decide whether to participate and how many shares to tender. Under applicable securities rules the offer period is typically at least 20 business days, which sounds generous until you realize you need tax advice, cash-flow planning, and possibly an exercise decision inside that window.
- Proration. If shareholders tender more shares than the buyer agreed to purchase, the offer is prorated — everyone sells a reduced, proportional amount. Tendering the maximum allowed does not guarantee you sell the maximum.
- Closing and settlement. Start to finish, a private-company tender offer commonly takes one to three months. Proceeds arrive as cash, usually with tax documents following early the next year.
One critical detail: most offers only accept shares, not unexercised options. If your equity is still in option form, you generally must exercise first — paying the strike price out of pocket — and then tender the resulting shares. That exercise step is where the biggest tax traps live, so understand your grant type before you click "participate."
Know Your Grant Type Before You Tender
The tax outcome of selling in a tender offer depends almost entirely on whether you hold incentive stock options (ISOs), non-qualified stock options (NSOs or NQSOs), or restricted stock units (RSUs). Many employees hold a mix and do not realize the tranches are taxed differently.
ISOs: The Best Treatment, and the Easiest to Accidentally Destroy
ISOs get special tax treatment, but only if you satisfy two holding periods: more than two years after the grant date and more than one year after the exercise date. Sell after meeting both and you have a qualifying disposition — the entire gain above your strike price is taxed as long-term capital gains.
Sell before either clock runs out and you have a disqualifying disposition. The spread at exercise (fair market value minus strike price) is recharacterized as ordinary compensation income, and only further appreciation after exercise gets capital-gain treatment. Most tender-offer sales of recently exercised ISOs are disqualifying dispositions, which surprises employees who assumed their "tax-advantaged" options would be taxed like stock.
Two ISO-specific gotchas deserve emphasis:
- No withholding on the disqualifying income. Unlike NSO income, which your employer withholds on like wages, income from an ISO disqualifying disposition is reported on your W-2 with no federal withholding taken. If you sell a large block, you can owe a five- or six-figure tax bill the following April with nothing prepaid. Plan for estimated tax payments in the quarter of the sale.
- The AMT interaction. Exercising ISOs and holding the shares creates an alternative minimum tax adjustment on the bargain element, which can generate AMT owed with no cash to pay it. Selling in the same calendar year as exercise via a disqualifying disposition generally eliminates that AMT adjustment — the income lands in the regular tax system instead. Employees who exercised ISOs months before a tender offer was announced should model both paths rather than assuming the AMT bill they feared is still coming.
NSOs: Simpler, but Withholding Rarely Covers the Bill
NSOs are taxed as ordinary income on the spread at exercise, and your employer withholds income and payroll taxes at that point, much like a cash bonus. When you later sell the shares in a tender offer, only the appreciation after exercise is a capital gain — short- or long-term depending on how long you held the shares after exercising.
The trap here is the withholding rate. Employers typically withhold on equity income at the supplemental flat rate (currently 22 percent federal up to $1 million), which is often well below your actual marginal rate once the sale pushes you into a higher bracket. Like the ISO seller, you may need to top up with estimated payments to avoid an underpayment penalty.
RSUs: Watch the Settlement Mechanics
At private companies, RSUs often carry double-trigger vesting: shares settle only when both a time-based schedule and a liquidity event are satisfied, and a tender offer sometimes counts as the liquidity trigger. When RSUs settle, the full fair market value is ordinary income with withholding. If your RSUs settle into the tender offer automatically, confirm what was withheld and what basis is reported — cost-basis errors on equity sales are among the most common and expensive mistakes on employee tax returns.
The Price Is Not Negotiable, but Your Decision Still Has Levers
You cannot haggle over the offer price, but several choices within your control materially change the outcome.
How Much to Sell
Offers typically cap participation at a fraction of your vested holdings, but selling the maximum is a choice, not a requirement. Consider three lenses:
- Concentration risk. If your company's stock is most of your net worth, you are doubly exposed: your salary and your savings depend on the same employer. Financial planners generally treat employer stock above 10 to 15 percent of a portfolio as a concentration worth trimming. A tender offer is often the first realistic chance to diversify.
- Need versus greed framing. Earmarking proceeds for concrete goals — an emergency fund, a home down payment, high-interest debt — leads to better decisions than trying to guess whether the next valuation will be higher. Nobody knows the future 409A.
- Dry powder for taxes. If exercising options to participate creates its own tax bill (AMT on ISOs held, ordinary income on NSOs), make sure the shares you are allowed to sell generate enough cash to cover it. Employees have ended up owing more in exercise-related taxes than their prorated sale proceeds.
Whether to Exercise Early for the Offer
If the offer accepts only shares and your options are unexercised, you must come up with the strike-price cash plus any exercise-triggered taxes before you see a dollar of proceeds. Run the full cash-flow math: strike cost, plus estimated exercise taxes, minus expected (possibly prorated) sale proceeds. If proration cuts your sale in half but you already paid the full exercise cost, the deal can flip from profitable to painful.
What the Price Tells You — and What It Does Not
A tender price at or near the last funding-round valuation, backed by sophisticated outside buyers, is a genuine validation signal. But a price set at the 409A valuation with a discount, or an offer funded entirely by the company with no outside buyer, carries less information. Treat the price as one data point about value, not a forecast. And remember that selling keeps you exposed to the remaining shares you hold — partial liquidity reduces concentration; it does not eliminate it.
Five Mistakes That Blindside First-Time Sellers
1. Forgetting That No One Withheld Taxes on the ISO Sale
This is the single most common tender-offer tax shock. Your W-2 shows the disqualifying-disposition income, your withholding does not cover it, and April brings a bill plus possibly an underpayment penalty. The fix is mechanical: estimate the tax in the quarter you sell and pay it, or increase withholding enough to hit a safe harbor.
2. Exercising ISOs Early in the Year and Selling Late
The AMT benefit of a same-year sale only works if exercise and sale fall in the same calendar year. Exercise in December and sell in the following January, and you can owe AMT on the bargain element for the exercise year while the cash arrives a year later. If a tender offer is rumored, time your exercise accordingly — and if you already exercised, confirm which tax year the closing will land in before celebrating.
3. Ignoring State Taxes
Equity income is generally taxed by the state where you worked when it was earned, and a large tender-offer sale can create multi-state filing obligations if you vested shares while living in different states. A move from California to Texas mid-vesting does not move the California-source portion of the gain with you. High-tax-state employees should get state-specific advice rather than assuming their current address controls everything.
4. Tendering Without Reading the Eligibility and Proration Terms
Former employees are often capped at lower amounts or excluded entirely. Some offers exclude shares acquired within a lookback period. And proration means your "sell the max" election may fill only partially — a nasty surprise if you already exercised options in full reliance on selling all of them. Read the offer memo like the contract it is.
5. Treating the Tender Price as the Company's True Value
The tender price reflects what one buyer (or the company) will pay for a capped quantity of shares on one date, under transfer restrictions, with limited information rights. It is not a public-market quote. Basing major life decisions — quitting, buying a house with no margin — on the assumption that every future liquidity event will price at least this high is how paper millionaires become cautionary tales.
A Pre-Tender Checklist
Two to four weeks before the election deadline, work through this list:
- Inventory every grant. List each ISO, NSO, and RSU tranche with grant date, exercise date, strike price, and vested share count. Your holding-period status and tax treatment flow from these dates.
- Confirm what you can actually tender. Shares only, or options too? Current employees only? Any lookback exclusions?
- Model the taxes by tranche. Compute ordinary income versus capital gain for each lot under both sell and hold scenarios, including AMT for ISOs and state tax.
- Stress-test proration. Recompute the math assuming you sell half of what you tender. If the deal still works, proceed with confidence.
- Arrange the cash. Strike-price payments and estimated taxes are due before or alongside settlement — line up the funds now.
- Get advice proportional to the stakes. A few hundred dollars for a CPA or equity-compensation-savvy adviser is cheap insurance when the decision involves tens of thousands in taxes.
Track the Sale Like the Business Transaction It Is
A tender-offer sale generates the kind of paperwork that gets lost exactly when you need it: offer memos, exercise confirmations, settlement statements, and a W-2 whose equity lines you must reconcile against your own records. Keep a dedicated folder — digital or physical — with every document, and log each lot's grant date, exercise date, strike price, sale price, and tax paid. When the following year's tax forms arrive, reconcile them against your log before filing; basis and withholding errors on equity transactions are common, and the IRS notices go to you, not your employer.
Good record-keeping also matters for the shares you keep holding. Each retained lot carries its own holding-period clock and cost basis, and the next tender offer — or the IPO — will demand the same analysis all over again. A clean ledger today is a faster, cheaper decision next time.
Keep Your Equity Records Organized From Day One
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