83(b) election deadline and tax risk radar
Enter the date your stock was transferred and it computes the filing deadline the IRS actually publishes — including the weekend and holiday rule most calculators skip. Then it models what missing the window does to your tax.
Educational, not tax advice. This is arithmetic on a published rule and on numbers you supply. It cannot confirm your deadline or your tax position, and an 83(b) election cannot be revoked without IRS consent — so treat it as preparation for a conversation with a tax adviser, not a replacement for one.
Educational, not tax advice. This computes a date from the rule the IRS publishes and a tax comparison from numbers you type. It does not know your facts, cannot confirm your deadline, and is not a substitute for a tax adviser — and an 83(b) election is not revocable without IRS consent, so it is worth a real conversation.
1. The 30-day deadline
2. What filing is worth, on your assumptions
- Without the election, about $53,326 of tax falls due as the stock vests — years before any exit, with no shares sold to pay it. That cash-flow problem is often the part that actually hurts, whatever the totals say.
- The total tax difference here is $105,375, roughly 2.6% of gross proceeds, because a large share of the appreciation lands before the stock has finished vesting and is recharacterised as ordinary income.
- $475,728 of gain is short-term without the election, because each vesting event starts a new holding period. With the election the clock runs from the transfer date instead.
- Not modelled: state and local tax, payroll or self-employment tax, the net investment income tax, AMT, and any QSBS exclusion — which needs five years of holding measured from a date the election also moves.
Never having to compute this under pressure
A missed 83(b) is almost never a decision. It is a grant that was approved in a board consent, papered a fortnight later, and filed by nobody — because no single system was holding the grant date, the 30-day clock and the signed election in the same place. Lovie records the transfer date on the grant itself and tracks the filing alongside it, so the deadline is attached to the equity rather than to somebody's memory.
We will tell you the date and hold the paperwork. We will not tell you whether to make the election — that is a decision for you and your tax adviser, on your facts.
What happens if you miss the 83(b) election deadline?
Miss it and Section 83(a) applies instead: the stock is taxed as it vests, not at grant. Each vesting date recognises ordinary income on that tranche's fair market value, at ordinary rates, in a year when nothing can be sold to pay the bill.
- The tax hit moves to vesting. Under §83(a) each tranche is taxed when it substantially vests, at its fair market value on that date less anything you paid — so a four-year schedule becomes four years of taxable events instead of one.
- Appreciation is reclassified as ordinary income. Growth between the grant and each vesting date stops being capital gain and becomes compensation income, taxed at your marginal rate rather than the long-term rate.
- The holding period restarts at every vest. The capital gains clock runs from each vesting date rather than from the grant, so shares sold soon after vesting can be short-term — and the five-year QSBS clock is affected too.
Where the popular version of this answer is wrong
Most pages on this subject show a chart comparing your entire exit taxed at ordinary rates against your entire exit taxed at capital gains rates. That is not what happens. Without an election you pay ordinary rates on the appreciation up to each vesting date, and the growth from there to the exit is still a capital gain — your basis stepped up each time you paid tax. Presenting it the other way inflates the number by a wide margin, and once a reader spots that, nothing else on the page is believable.
The tool above models it properly, which means the total-tax gap it reports is sometimes smaller than you might expect. Move the exit date and you will see why: if almost all of the value arrives after the shares have finished vesting, there is little appreciation left to recharacterise. If the company appreciates hard during the vesting period, the gap is large.
The real exposure is timing, not the headline rate
The number worth staring at is the one labelled “tax owed while the stock is still illiquid”. Without an election, tax becomes due in the year each tranche vests, on paper value, in a company whose shares nobody can sell. Founders have taken loans against houses to pay that bill. A modest total-tax difference and a real cash-flow crisis can sit on the same cap table, and the second one is what actually ends badly.
The deadline rule, in the IRS's own words
The instructions to IRS Form 15620, Section 83(b) Election state that an election “must be filed no later than 30 days after the date the property was transferred”, and that under IRC §7503 an election is timely if it is postmarked by the next business day where day 30 falls on a Saturday, Sunday or legal holiday. That form — revised April 2025 — is worth knowing about on its own: for years the only route was a hand-drafted statement, and plenty of guidance still says so. The written statement satisfying Treas. Reg. §1.83-2 remains a valid alternative, and Revenue Procedure 2012-29 contains the IRS's sample language. The statute itself is IRC §83.
Two details that catch people out. The 30 days run from the transferdate, which is not always the date on the board consent — if the paperwork was signed a week after approval, you need to know which date governs. And the 30 days are statutory, set in §83(b)(2), which is why the usual discretionary relief for late elections is not available. That is the reason this deadline gets treated differently from almost every other date on a founder's calendar.
How Lovie keeps this from becoming a story
A missed election is rarely a decision anybody made. It is a grant approved in a board consent, papered a fortnight later, and filed by nobody — because the transfer date, the 30-day clock and the signed election lived in three different places. Lovie records the transfer date on the grant itself and tracks the filing against it, so the deadline is a property of the equity rather than something in an inbox. That is the whole claim: not that software makes the tax decision for you, but that it stops the date from going missing.
Where this fits
An 83(b) election is priced off a fair market value, and where that value comes from is the subject of the 409A valuation timing checklist. If the grant in question is options rather than restricted stock, the ISO vs NSO tax calculator covers the treatment that applies instead, and the vesting schedule simulator shows the schedule this page is taxing. The 83(b) election glossary entry is the short definition, and the cap table glossary covers the rest of the vocabulary. The product is at Lovie CapTable.