Tax Strategies

Correcting Cost Basis of Shares from NSOs Post-IPO

If you exercised NSOs pre-IPO and your company eventually IPOs, the cost basis your broker lists for your NSOs will very likely be wrong (and needs to be corrected on your taxes)

How-toIntermediate2 min readBy Kris Barney

Strategy Overview

When you sell shares, you recognize either a gain or loss --> calculated as the selling price minus the purchase price (also know as cost basis). In nearly all cases this is really simple and that's that. But due to a few (annoying) quirks, shares acquired via exercising an NSO when the company was still private (i.e. pre-IPO) very frequently have an inaccurate cost basis relative to your tax basis (which is what you care about). This isn't an error; the broker is doing what they are technically suppose/required to do. But it can cause an individual to make incorrect tax decisions, and/or report an incorrect amount of gain/losses on their tax return if it isn't corrected.

Tax Details

Your cost basis technically means the price you purchased shares at. For example, if you purchase 100 shares of MSFT at $300 per share, your cost basis would be $300 per share (captain obvious strikes again!). But what if you purchased 100 shares via an NSO with a strike price of $1 when the FMV is $5?

  • Per NSO taxation rules, you will (1) pay $1 per share to buy the shares, (2) owe income tax of $4 per share ($5-$1), and thereafter the shares will have a $5 per share tax/cost basis

  • But you "technically" bought the share(s) for $1

  • Post-IPO when your shares are transferred to a broker, the brokerage firm is required to use/list the "technical" cost basis of $1 per share instead of your tax/cost basis of $5 per share

The Fix Is Relatively Simple (Though VERY Frequently Messed Up):

  • First and foremost, be keenly aware that this is occurring. Most individuals aren't aware that this happens; they simply think their tax basis ported over and all is good. This oversight will result in an incorrect tax calculation (and very likely you overpaying taxes).

  • Inform your CPA when you sell these share so that she/he update the tax basis to correct amount. In the year(s) you sell the exercised NSO shares, inform your tax preparer + provide them with your exercise confirmations. Your tax preparer will fill out a "cost basis adjustment" on your tax return to correct the cost basis (i.e. in the example above, from $1/share to $5/share).

Key Considerations/Flags/Strategy

These sections are not applicable for this tax "strategy". Ensuring that you utilize the correct cost basis for your NSOs is ensuring you file your taxes correctly -> which is something we always recommend you do.

Example

CorrectNSOBasis Img1

Work with 30/40 Wealth

Have a big equity or tax decision ahead?

We're a fee-only fiduciary for tech employees with a lot of company equity. We build your multi-year plan: when to exercise options, what to sell and when, and how to cut the tax bill. Then we stay with you for the years that follow.

You're likely a fit if:

  • You have $2M+ in company equity, including options
  • Your next big decision is coming up: an IPO or lockup, a tender offer, exercising options, selling a large position, or leaving your company
  • You want ongoing help with all of it: your equity, taxes, investments and the plan that ties them together
Kris Barney

Kris Barney, CFA, EA

$750M+ in equity compensation advised

Fees from $12,500 a year, based on the assets we manage

We take on 1–2 new clients a month

Book a 30-minute fit call →

Free and no obligation. If we're not the right fit, we'll say so.

See who we work with →

Most Similar

Selected by content similarity, not just shared category.

Next Step

Want this applied to your situation?

A 30-minute consult will tell you whether the framework in this article applies cleanly to your equity package — and if so, what the next three moves are. No pitch.