83(b) elections explained: the 30-day decision that saves founders millions

What is an 83(b) election?

Section 83(b) of the Internal Revenue Code lets a recipient of restricted stock choose to be taxed on the full value of that stock at the time it's granted, rather than as it vests over time. For founders, this is almost always the right call because restricted stock granted at incorporation is typically worth close to nothing — often just the par value paid for the shares — so the resulting tax bill is minimal or zero.

Without the election, the IRS taxes you on the fair market value of each tranche of stock as it vests, which is usually monthly or after a one-year cliff. If your company's valuation has grown between the grant date and the vesting dates (the entire point of starting a company), you'll owe ordinary income tax on that appreciation with every vesting event, even though you haven't sold any shares or received any cash to pay the tax.

Why this matters so much for founders

Say a founder is granted 1,000,000 shares at incorporation for $0.0001 par value each ($100 total), subject to a standard four-year vesting schedule with a one-year cliff. If filed, the 83(b) election locks in that $100 total value as the taxable event — likely resulting in no meaningful tax owed, since fair market value approximates the purchase price at that early stage.

If the founder doesn't file and the company's common stock fair market value rises to $1.00 per share by the time of later vesting tranches (a realistic scenario after a priced seed or Series A round), the founder would owe ordinary income tax on hundreds of thousands of dollars of phantom income they haven't actually received in cash — a serious cash flow and tax problem.

The 30-day deadline is absolute

The election must be filed with the IRS within 30 calendar days of the grant or purchase date — not 30 business days, and with no extensions for any reason, including illness, bad advice, or simply not knowing the rule existed. The IRS has historically denied late elections even in sympathetic circumstances. If you miss the window, there is no fix; you're locked into standard vesting-date taxation for that grant.

This is one of the most unforgiving deadlines in startup finance, which is why many startup attorneys build 83(b) filing instructions directly into the stock purchase agreement paperwork at incorporation.

Who should file an 83(b) election?

• Founders receiving restricted stock subject to vesting at company formation.
• Early employees granted restricted stock (not stock options) before a priced round.
• Anyone early-exercising stock options and receiving unvested shares, since early-exercised shares are also subject to Section 83.

If you're granted stock options (ISOs or NSOs) that you exercise only as they vest, an 83(b) election typically isn't relevant in the same way — it applies specifically to restricted stock or early-exercised option shares still subject to a substantial risk of forfeiture.

How to file an 83(b) election

1. Confirm your grant date. This is the date your restricted stock purchase agreement is signed and shares are issued, not the date your company was formed.
2. Prepare the election letter. Include your name, address, SSN or ITIN, a description of the stock, the grant date, the fair market value per share, the amount paid (if any), and a statement that you're electing under Section 83(b).
3. Sign and mail it to the IRS service center where you file your personal tax return, via certified mail with return receipt requested — this is your proof of timely filing.
4. Mail within 30 calendar days of the grant date. Count every calendar day, including weekends; if day 30 falls on a weekend or holiday, file earlier rather than relying on the next business day under some interpretations.
5. Provide a copy to your employer/company and keep a copy for your own records.
6. Attach a copy to your federal income tax return for the year of the grant when you file in the spring.

Some IRS offices no longer return a stamped confirmation copy, so the certified mail receipt is your primary proof the filing was timely. Keep that receipt indefinitely — ideally scanned and stored alongside your cap table and LLC vs C-corp formation documents.

Risks of filing an 83(b) election

Filing isn't risk-free. You're prepaying tax on stock you haven't fully earned yet and may never earn if you leave the company before it fully vests. If the company fails or the stock becomes worthless, the tax you already paid is generally not refundable, though you may be able to claim a capital loss in some circumstances — consult a CPA on your specific situation. For most founders at incorporation, the dollar amount at risk is small (often under a few hundred dollars of tax), making the decision low-risk relative to the potential future tax savings.

83(b) election vs. no election: side-by-side

	With 83(b) election	Without 83(b) election
Taxable event	Grant date, one time	Each vesting date
Taxable value	Fair market value at grant (often near $0)	Fair market value at each vesting date (can be much higher)
Capital gains eligibility	Holding period starts at grant	Holding period starts at each vesting date
Risk if stock is forfeited	Tax paid is generally not refunded	No tax owed on unvested/forfeited shares

Filing also starts your capital gains holding period clock at the grant date rather than at each vesting date, which matters for qualifying for long-term capital gains rates and potentially QSBS Section 1202 exclusions down the road, since both require holding periods measured in years.

Coordinating with your broader founder finances

An 83(b) election is one of several time-sensitive decisions founders face in their first weeks of incorporation, alongside choosing an entity structure, setting up payroll, and opening a dedicated business bank account. Getting the paperwork right early avoids compounding tax problems later — much like paying yourself correctly as a founder avoids payroll tax surprises. A platform like Initio Treasury can help you keep tax-related records and reserves organized as your company grows, though the 83(b) filing itself must go directly to the IRS by mail.

Because the stakes and deadline are unforgiving, loop in a startup attorney or CPA as soon as your stock purchase agreement is signed — not after the 30 days have started to run out.