---
title: "What Is NSO?"
term: "NSO"
description: "NSO — non-qualified stock option — is an employee stock option that does not meet ISO tax requirements, so exercise typically triggers ordinary income tax on the spread between strike price and fair market value."
date: 2026-07-25T00:00:00.000Z
updated: 2026-07-25T00:00:00.000Z
topics: ["equity"]
source: https://venturecapitaltracker.com/glossary/nso
---

# What Is NSO?

> NSO — non-qualified stock option — is an employee stock option that does not meet ISO tax requirements, so exercise typically triggers ordinary income tax on the spread between strike price and fair market value.

**NSO** (non-qualified stock option) is a type of employee or contractor equity grant taxed under ordinary income rules at exercise — the most flexible and common option type beyond ISO limits.

### How it works

The company grants options with a **strike price** at fair market value on grant date. After vesting, the holder exercises — pays strike × shares to the company — and receives stock. For NSOs, the spread (FMV minus strike) is generally **compensation income** subject to income and payroll taxes at exercise, regardless of whether shares are sold.

Companies often use NSOs for advisors, international staff, and employees who exceed **ISO** $100K annual vesting limits. NSOs can have longer exercise windows after departure if the plan allows, though post-termination exercise periods vary.

409A valuations set strike prices; exercising into illiquid private stock creates tax due without cash unless a secondary or tender occurs.

### Why it matters

- **Founders:** Design equity plans knowing NSO vs ISO mix affects recruiting narratives and admin. Tender offers and liquidity programs help employees pay NSO exercise taxes.
- **Operators:** Model exercise scenarios before clicking — a high FMV spread can produce a large tax bill on paper gains you cannot sell yet. Some exercise-and-sell or cashless exercise programs mitigate this in late-stage companies.

### Common mistake

Treating NSOs like ISOs for tax planning. ISOs may defer taxation until sale if holding periods are met; NSOs generally do not.

### Related ideas

See also [NSO tax](/glossary/nso-tax), ISO, [equity incentive plan](/glossary/equity-incentive-plan), and 83(b) elections (for restricted stock, not options).

## FAQ

### What is NSO in simple terms?

An NSO is a stock option that lets you buy company shares at a set strike price. Unlike ISOs, exercising an NSO usually creates taxable wage income immediately on the difference between strike and current value — even before you sell shares.

### Why does NSO matter?

For founders, NSOs are the default for contractors, non-U.S. employees, and amounts above ISO limits. For operators, NSO exercise requires cash for taxes and may need same-day sales to cover withholding — plan with a tax advisor.


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Source: https://venturecapitaltracker.com/glossary/nso