The 83(b) election: 30-day deadline and filing in 2026

The 83(b) election is a one-page IRS letter that taxes your restricted stock at grant instead of at vesting. You have 30 days from the grant date with no extensions. File by certified mail with return receipt, keep the stamped copy, and expect to owe ordinary income tax only on the spread at grant, which is usually near zero.

Miss the 83(b) election and the bill can wipe out your equity upside. A founder with 1 million shares at $0.001 per share who skips the 30-day window could owe over $1.8 million in federal tax alone if those shares vest at $5, per Otterz's 83(b) Filing Guide. File on time and you owe tax on roughly $1,000 of grant value. The gap between those two outcomes is the entire point of this article.

The 83(b) election deadline runs from grant, not paperwork

Your 30-day clock starts on the grant date, not the day you sign the paperwork. The grant date is typically the date your board approved the restricted stock grant, per Otterz. If your board consent is dated the 1st and counsel sends the stock purchase agreement on the 12th, you have 19 days left, not 30.

Cooley GO states the election must be filed within 30 days of the grant or it is void, with no extension available, per Cooley GO. Treat the grant date as a hard deadline the moment you see it on a board consent. Calendar it immediately, and file a week early if you can.

How to file an 83(b) election with the IRS in 2026

As of early 2026, 83(b) election filing must still be done by mail, per Otterz. The IRS introduced Form 15620 as a standardized election form, but paper filing remains the compliant method until the agency enables electronic submission.

The full process:

1. Confirm the grant date on your board consent or stock purchase agreement. The 30-day window starts here.
2. Complete Form 15620 or draft your own election letter meeting the regulatory requirements.
3. Sign and date the election. Include a spouse's signature if filing jointly in a community property state.
4. Mail the original to the IRS Service Center where you file your personal tax return.
5. Use certified mail with return receipt requested, per Cooley GO. Write the certified mail number on your cover letter copy.
6. Retain proof: the stamped certified-mail receipt and the signed return receipt are your only evidence of timely filing.
7. Provide a copy to the company for its records.
8. Attach a copy to your personal tax return for the year of the grant.

The certified-mail step is not optional. If the IRS loses your filing, the return receipt is what proves you met the deadline.

83(b) late filing: what happens if you miss the deadline

A missed 83(b) deadline is effectively unfixable. The election is void, and relief is generally only granted in narrow "mistake of fact" situations described in the IRS Form 15620 instructions.

The tax mechanics of skipping the election: each vesting tranche counts as ordinary income equal to the spread between fair market value at vest and what you paid for the stock. The 83(b) election exists to convert that future appreciation from ordinary income rates of up to 37% into long-term capital gains rates of up to 20%, per Otterz.

That means you pay top-bracket tax on paper gains, using cash you do not have, every time shares vest. For a high-growth startup, this is the scenario that bankrupts founders who would otherwise have been rich.

Founder 83(b) mechanics: when it is worth it

For almost every founder of a Delaware C-corp with vesting on common stock, file the 83(b). The tax due at grant is usually zero or a few dollars of spread. The downside of skipping scales with your exit value.

Two situations where founders sometimes hesitate:

• Fully vested stock at formation: If nothing is subject to a risk of forfeiture, no 83(b) is required. But if there is reverse-vesting or a company repurchase right on unvested shares, file it anyway.
• Non-C-corp structures: Elections can apply to restricted equity in certain LLC or partnership grants, but the rules differ. Get counsel to confirm.

A 2026 Carta survey on equity tax liability found that 63% of employees do not know how to reduce the tax liability on their equity. Founders who file an 83(b) on day one are ahead of almost everyone else in the cap table.

One last trap: an 83(b) election cannot be revoked after filing except with IRS consent in very limited circumstances, per IRS Form 15620 guidance. Once it is in the mail, you own the tax treatment.

FAQ

What is the 83(b) election deadline? 30 days from the grant date, meaning the date your board approved the restricted stock grant, per Cooley GO. There are no extensions. If the 30th day falls on a weekend or holiday, file before the weekend to be safe.

How do I send an 83(b) election to the IRS? Mail the signed election, either IRS Form 15620 or a compliant letter, by certified mail with return receipt requested, to the IRS Service Center where you file your personal return. Write the certified mail number on your cover letter copy. Keep the return receipt as proof of timely filing.

What happens if I forget to file 83(b)? The election is void and cannot be refiled. You will be taxed on each vesting tranche at ordinary income rates on the spread between fair market value and your purchase price. On a meaningful exit, this can cost hundreds of thousands to millions in avoidable tax.

Can I file 83(b) electronically? No. As of early 2026, 83(b) elections must still be filed by mail, though the IRS has signaled that Form 15620 may enable future electronic filing. Until that changes, certified mail is the only compliant method.

Is 83(b) election mandatory? No, it is optional. For founders and early employees receiving restricted stock with vesting, filing is almost always the right call because the tax due at grant is usually near zero. Skipping the election is a default that rarely makes financial sense.