Did I Miss My 83(b) Election Window?
What Early Founders Need to Know Before Giving Themselves Equity.
An 83(b) election can seem like a tiny administrative detail in the middle of building a company, perfecting your fundraising strategy and putting out fires.. But if you miss the 30-day window, that “small” filing can turn into a very expensive tax problem later.
The 30-day window doesn’t care how busy you were.
Miss it and you pay ordinary income tax every time your shares vest, based on the company’s value at that time. File it and you pay tax once, at the low value on day one.
What the 83(b) Election Does
An 83(b) election is a letter (now a standardized IRS form) you send to the IRS within 30 calendar days of receiving vesting or restricted stock. It tells the IRS: tax me now, at today’s value, not later as shares vest.
For most founders, that is the whole point: pay the tax early, when the company is still worth little or nothing.
Two paths exist when you receive founder shares:
- With 83(b) filed: You pay taxes on the grant-date value (usually near zero). Each vest is not a tax event. When you sell, you pay capital gains on the full appreciation.
- Without 83(b) filed: Each vesting event is an ordinary income tax event at the stock’s fair market value at that time. If the company has grown, the tax bill grows with it.
When the 30-Day Clock Starts
Founders often misunderstand when their 30 day window to file begins. The clock starts on the date stock is transferred, which is typically indicated on the board approval or the date reflected on your equity documents. Not when you sign later or receive your paperwork.
Founders routinely discover they are already a week or two past the deadline before they even open the documents. There is no grace period. The IRS does not accept late filings.
The New IRS Form to Use
In April 2025, the IRS released IRS Form 15620, the official standardized form for making a Section 83(b) election. Before this, founders typically drafted custom election letters, which created inconsistency and drafting risk.
The custom letter approach may still be used, but Form 15620 is now the cleaner, lower-risk choice with a standardized approach.
How to File It Correctly
As of now, the 83(b) election still generally needs to be mailed.
A typical filing process looks like:
- Complete the IRS Form 15620.
- Mail to the IRS with 30 days of the stock transfer date (make sure you send to the right address based on your state residency).
- Use certified mail with a return receipt.
- Keep copies of everything.
- Send a copy to the company for its records.
The postmark date must fall within 30 days of the transfer date. A day past that and the election is gone permanently.
Common Founder Mistakes
Mistake #1: Counting Days from the Wrong Date
Founders often count from the day they received or signed the documents. That can be too late. Confirm the actual transfer or issuance date before calculating the deadline.
Mistake #2: Waiting Until the Documents Feel “Final”
The 83(b) deadline does not pause because the paperwork is confusing or still being circulated. Once the stock has been transferred, the clock may already be running.
Mistake #3: Assuming Early Exercise Doesn’t Require One
An 83(b) election is not only relevant for founder restricted stock. If you early exercise unvested options, you may also need to file an 83(b) election because you now hold restricted property.
Mistake #4: Not Keeping Proof
Mailing the form is not enough. Keep the signed form, mailing receipt, tracking, and delivery confirmation.
Quick Founder Self-Check
- Do I know the exact date my stock was granted or board-approved?
- Have I counted 30 calendar days from the date, not from when I received the paperwork?
- Have I sent the form by certified mail with a return receipt?
- Did I keep proof of mailing and delivery?
- Did I keep a copy and send one to the company?
- If I early-exercised options, did I file a separate 83(b) for those as well?
If you think the deadline may have passed, confirm the actual transfer date with counsel before assuming it is too late. Equity may have to be reissued.
Bottom Line
The 83(b) election is one of those early founder tasks that feels small but can have huge consequences.
It is simple, inexpensive, and easy to overlook. But once the 30-day window closes, the opportunity is generally gone.
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Sources Used
- The Startup Law Blog, “83(b) Election Guide: What Startup Founders Must Know (2026)” — https://www.thestartuplawblog.com/blog/83b-election-guide/
- Carta, “What is an 83(b) Election? Tax Benefits & How to File Form 83(b)” — https://carta.com/learn/equity/stock-options/taxes/83b-election/
- SpryTax, “83(b) Election Guide 2026” — https://sprytax.com/guides/83b-election/