Double-trigger RSUs, and the bill that arrives at IPO

Private-company RSUs need two things to happen before you own anything: time, and a liquidity event. That structure protects you from being taxed on shares you cannot sell — and stores up several years of income to land in a single tax year when the company finally goes public.

Guide Last verified 2026-07-27 How we verify

In short

Two conditions must both be satisfied: a time condition, which vests on a schedule, and a liquidity condition, which vests on an IPO or acquisition. Neither alone gives you anything.
Until both are met you own nothing, are taxed on nothing, and can lose everything by leaving. The time-based portion vesting does not make it yours.
When the liquidity condition finally trips, every previously time-vested unit settles at once. Four years of compensation becomes one year of income, taxed at the rates that produces.
Withholding at that moment is the flat supplemental rate — 22% until $1,000,000 of supplemental wages for the year and 37% above it — against a real rate that is usually higher on the first tranche.
Most IPOs impose a lock-up of around six months. You are taxed on the settlement-date value and cannot sell until the price has moved, in either direction.

A restricted stock unit at a public company is simple: it vests on a date, you receive shares, and the value on that date is wages. At a private company that arrangement would be intolerable, because you would owe cash tax on shares you cannot sell to anyone. The double-trigger structure exists to prevent exactly that, and it works.

What it also does is defer the problem rather than remove it. Years of vesting accumulate untaxed, and then the whole accumulated amount becomes income on a single day — usually the day the company goes public, which is also the day a lock-up prevents you from selling any of it. That combination catches out a great many people, and it is entirely predictable in advance.

Run your own numbers: RSU Withholding Shortfall Calculator.

What the two triggers actually are

The time-based condition is the familiar one: a four-year schedule, usually with a one-year cliff and quarterly or monthly vesting after it. Satisfying it alone changes nothing you can see. The units are marked as time-vested in your equity portal and remain entirely notional.

The liquidity condition is satisfied by a specified event — typically an initial public offering, sometimes a change of control, occasionally a tender offer or a defined date after one of those. Its precise definition lives in your grant agreement and varies more than people assume.

Under §83(a) you are taxed when property is transferred to you and is no longer subject to a substantial risk of forfeiture. While the liquidity condition is outstanding, no shares have been transferred at all, so there is nothing to tax. That is the whole design.

The liquidity condition also has to be drafted carefully to avoid §409A treating the arrangement as deferred compensation with its own penalties. This is why the wording is so uniform across companies and so rarely negotiable.

Leaving before the second trigger

This is the part worth understanding before you accept the offer rather than after. In most standard plans, unsettled units are forfeited when you leave — including units that are fully time-vested.

The practical consequence is that four years of vesting can produce nothing at all if you resign eighteen months before the company lists. Unlike options, there is no ninety-day window to exercise and no cash you could pay to keep them. They simply lapse.

Some plans soften this, most commonly by continuing to honour time-vested units if a liquidity event occurs within a defined period after departure. It is worth reading your own plan rather than assuming either the harsh or the generous version, because both are common.

The day it all lands

When the liquidity condition is met, every unit that has already satisfied the time condition settles simultaneously. Someone who joined four years before an IPO recognises four years of accumulated grants as ordinary income on one date, at whatever the shares are worth then.

Two things make the resulting bill worse than the raw number suggests. The income stacks on top of a full year of salary, so most of it is taxed in the highest brackets that year rather than spread across four. And withholding is at the statutory supplemental rate, which is a flat 22% until the year’s supplemental wages pass $1,000,000 and 37% above that — a rate that is systematically too low on the first million for anyone in this position.

Companies typically handle the mechanics by selling a portion of the shares to cover withholding, which is helpful but does not close the gap between what was withheld and what is owed. That difference is settled on your return the following April, and it is frequently substantial.

The lock-up is the sharp edge. You are taxed on the value at settlement, and you usually cannot sell for roughly six months. If the price falls over that period you have paid ordinary income tax on a figure you will never realise, and the resulting capital loss offsets only $3,000 of ordinary income a year.

The §83(i) election, and why almost nobody uses it

Congress noticed the problem and legislated for it. §83(i) lets a qualified employee of an eligible private corporation elect to defer the income tax on settled units for up to five years, which is exactly the relief the situation calls for.

The catch is in the eligibility. An eligible corporation must operate a written plan granting stock options or restricted stock units to at least 80% of its United States employees in that calendar year, with the same rights and privileges. That threshold is measured on the grants made in the year, and the great majority of companies do not meet it — equity is usually concentrated rather than distributed that broadly.

Where it is available the election must be made within thirty days of the units becoming substantially vested, and it defers income tax but not Social Security and Medicare. In practice the provision is much better known than it is used, and you should confirm whether your employer qualifies rather than assuming the option exists.

What to do about it in advance

Find out how your plan defines the liquidity event and what happens to time-vested units if you leave first. Both are in the grant agreement.
Estimate the settlement well before it happens. The number of time-vested units is known; only the price is not, and a range is enough to see the shape.
Expect the withholding to be short and plan for the balance. A large settlement early in a year is withheld at 22% while the marginal rate on it is far higher.
Consider a quarterly estimated payment in the quarter of settlement rather than waiting for April, since underpayment interest is charged period by period.
Decide in advance what you will do at the end of the lock-up. Concentrated single-stock exposure is a risk you took involuntarily and can choose to stop taking.

None of this changes the tax. What it changes is whether the tax is a planned expense or a surprise arriving in an April when the shares are worth less than they were when you were taxed on them.

Questions

My units are fully time-vested. Do I own the shares?

No. Under a double-trigger structure the time condition is only half of what is required, and until the liquidity condition is also satisfied nothing has been transferred to you. You hold a contractual right that can still lapse.

This is the single most common misunderstanding in private-company equity, largely because equity portals display time-vested units in a way that looks like ownership.

Is a double trigger better or worse than a single trigger?

Better, on balance, and the alternative is genuinely worse. A single-trigger RSU at a private company would produce ordinary income the moment it time-vested, giving you a cash tax bill on shares with no market and no way to sell any to pay it.

What you give up is control over timing. A single trigger spreads income across years at whatever the shares were worth each time; a double trigger concentrates it into one year at one price. The concentration is the cost of the protection.

Does a tender offer count as the liquidity event?

Sometimes, and it is worth checking rather than guessing, because the consequences are large. Many plans define the trigger narrowly as an IPO or a change of control, in which case a company-run tender changes nothing about your units.

Others define it more broadly. Where a tender does trip the condition, all time-vested units settle and become taxable even though you may only be selling a fraction of them — which means finding cash for tax on shares you are keeping.

Why was so little withheld when my units settled?

Because withholding on supplemental wages is a flat statutory rate rather than your actual rate. It is 22% until your supplemental wages for the year reach $1,000,000, then 37% on the excess. Someone whose real marginal rate is 35% or 37% on the first tranche is under-withheld from the first dollar.

The gap is settled on your return. It is a known and calculable amount rather than a mistake by your employer, who is following the regulation exactly.

Can I do anything about the lock-up?

Rarely. Lock-ups are contractual commitments to the underwriters and are not usually waivable for individual employees, though some recent listings have used staged releases tied to price or time rather than a single cliff.

What you can do is set expectations correctly: you owe tax on the settlement-date value regardless of what the price does afterwards, so treat the shares released at the end of the lock-up as a position you already paid for rather than as a windfall.

What happens if the company is acquired instead of going public?

Usually the liquidity condition is met and everything settles, often as cash rather than shares. That is in one sense cleaner — you receive money at the same moment you are taxed, and there is no lock-up.

Unvested units are a different matter and depend entirely on the deal. They may be assumed by the acquirer, converted, cashed out on the original schedule, or accelerated. That negotiation happens above your head and the outcome varies enormously between transactions.

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Sources

Everything asserted above traces to one of these. We cite the statute, the regulation, or the IRS directly — never another commentary site.

This guide is educational information, not tax, legal or investment advice, and reading it creates no professional relationship. Equity compensation interacts with the rest of your return in ways a single article cannot see. Before acting on anything here, take it to a qualified tax adviser.