Quick answer: neither award is automatically better
RSUs usually avoid an exercise payment; ISOs give you a choice about buying shares, but that choice has a cost and a deadline. An RSU offer can still have difficult settlement or forfeiture conditions. An ISO offer can require cash and create tax exposure before you can sell. Prioritize a salary and bonus you can live on, then compare the written equity terms.
If the employer has only given you a unit count or a headline “value,” you do not yet have enough information to choose. Use the startup offer analyzer to put the grant alongside your salary, bonus, role and location—not to predict an exit.
RSUs and ISOs are awards, not share classes
Restricted stock units (RSUs) are contractual rights that settle under the plan’s conditions. They are not already-owned shares. Incentive stock options (ISOs) are employee options that may qualify for special US federal tax treatment if statutory requirements are met.
Common and preferred stock describe the rights attached to shares. RSUs and ISOs describe how you receive or buy them. Ask which share class your award ultimately delivers.
The differences that affect your offer
| Question | RSU | ISO |
|---|---|---|
| Do I pay to exercise? | Typically no exercise price; tax withholding may still require cash or shares. | Yes: the exercise price × options exercised. |
| When do I own stock? | After settlement in shares, not simply at grant. | After exercise, subject to the agreement’s restrictions. |
| Can I sell immediately? | Not necessarily. Private-company shares may have no market or have transfer limits. | Not necessarily. Exercise does not create liquidity. |
| What changes after leaving? | Forfeiture, vesting and settlement depend on the agreement. | A contractual exercise deadline applies; tax qualification has separate timing rules. |
A worked exercise-cost example
Suppose an offer includes 10,000 options with a $2 exercise price. Exercising all of them costs $20,000, before any tax or fees. If 10 million shares is the correct fully diluted denominator including the grant, the award represents 0.1% before future dilution. That percentage does not establish a sale payout.
An award of 10,000 RSUs may avoid that exercise payment, but its settlement conditions, withholding, share rights and sale restrictions still matter. Do not compare either award solely by multiplying units by a funding-round share price.
US tax risks: ISO does not mean tax-free
Qualifying ISOs generally do not produce regular federal income tax at grant or exercise, but an exercise spread can affect alternative minimum tax (AMT). The sale and holding periods affect the eventual treatment; state and non-US rules can differ.
The ISO statute generally requires employee status through three months before exercise, with exceptions. A company may allow a longer contractual exercise window without preserving ISO treatment for a later exercise. Ask a tax adviser before exercising, leaving, or accepting an extension.
RSU taxation depends on settlement and applicable rules. Private-company vesting and liquidity conditions can delay settlement or create forfeiture risks. An 83(b) election is not a general election for RSUs or unexercised options; it relates to qualifying transferred property, such as certain early-exercised restricted shares.
Which should you negotiate for?
RSUs may reduce exercise-cost risk; ISOs may offer favorable tax treatment if you meet the rules and can afford exercise. Neither is automatically better. Compare cash compensation first, then award size, exercise cost, vesting, settlement, forfeiture and liquidity.
- “What is the fully diluted share count, and what percentage does this grant represent?”
- “Which share class will I receive, and what investor preferences sit ahead of it?”
- “For RSUs, what triggers settlement and what happens if no liquidity event occurs?”
- “For options, what is the exercise price and post-termination exercise deadline?”
- “Can we improve salary, a signing bonus, refresh grants or change-of-control protection?”
What should I ask for before accepting?
Request the equity plan, proposed award agreement and a written explanation of the grant. An offer letter’s unit count alone does not resolve these questions.
- Ownership: confirm the fully diluted share count, whether it includes your grant, and the date of that estimate. New funding and grants can dilute your percentage.
- Your cash commitment: for ISOs, calculate options you plan to exercise × exercise price, then separately ask an adviser about tax exposure. For RSUs, ask how withholding is funded if shares cannot be sold.
- Timing: obtain the vesting schedule, RSU settlement conditions, award expiry and what happens to vested and unvested awards when you leave.
- Downside: ask about transfer restrictions, investor preferences and treatment in an acquisition. Review double-trigger acceleration if you want protection against losing unvested equity after a sale.
Negotiation starting point: “Before I trade salary for equity, could you confirm the grant’s ownership percentage, my potential out-of-pocket costs and what happens if I leave before a sale? If those risks cannot be reduced, can we improve salary or the signing bonus?”
Put these terms alongside your cash offer
Enter your salary, bonus, location, grant size and estimated share count, then select RSUs or ISOs. Include exercise price, settlement conditions and leaving deadlines in “Other information” so the source-grounded review can flag missing terms and useful employer questions.
Compare my offerCompDecoder’s salary ranges are directional estimates. Unverified equity is not counted as annual cash compensation, and an estimated ownership percentage is not a promised payout.