83(b) Election Deadline Calculator: 30-Day Window, Form 15620 and Mailing Address

Under Treas. Reg. §1.83-2(b), the election must be filed no later than 30 days after the date the property was transferred to you. The tool counts the transfer date as day zero and adds 30 calendar days. Stock received on October 1 must be filed by October 31.

The transfer date is usually the date in your stock purchase agreement or restricted stock agreement, or the date you early-exercise options. It is not the date you signed a board consent approving the grant, and it is not the date the certificate or Carta entry appeared. If the documents disagree, use the earliest plausible date.

There is no late-filing relief for a missed 83(b). The IRS does not accept elections after the window closes, so the vesting schedule then controls when you are taxed.

If day 30 lands on a Saturday, Sunday or legal holiday, IRC §7503 treats a filing on the next business day as timely. Two examples the tool handles:

• Transfer on Friday, September 18, 2026: day 30 is Sunday, October 18, so the deadline is Monday, October 19, 2026.
• Transfer on Tuesday, October 27, 2026: day 30 is Thursday, November 26 (Thanksgiving), so the deadline is Friday, November 27, 2026.

For paper filings, IRC §7502 treats a document as filed on the date of the U.S. postmark if it is properly addressed with postage paid. Sending it by USPS certified mail with a return receipt gives you proof of both mailing date and delivery. Keep the stamped receipt with your stock records permanently, because it is the evidence you will need at an acquisition or audit.

Our view: do not plan around the extension. File in the first week.

You have three valid ways to make the election:

1. Online through your IRS Online Account, using Form 15620. Since mid-2025 the IRS has let taxpayers complete and submit Form 15620 electronically after signing in with ID.me identity verification. You get an on-screen confirmation and can download the filed form.
2. On paper using Form 15620 (Section 83(b) Election), signed and mailed.
3. On paper using a written statement that contains everything Treas. Reg. §1.83-2(e) requires: your name, address and taxpayer ID, a description of the property, the transfer date and tax year, the restrictions, fair market value at transfer, the amount you paid, and a statement that you furnished the required copies.

Form 15620 is optional. Use one method only, not both. Founders who cannot complete ID.me verification, which is common for non-US founders without an SSN, should mail a paper election.

Treas. Reg. §1.83-2(c) says to file with the IRS office where you file your income tax return. For most individuals that is the Form 1040 no-payment address for your state on the IRS 'Where to file paper tax returns' page. As listed on that page when we checked it on October 17, 2026:

Each address begins 'Department of the Treasury, Internal Revenue Service'. The IRS changes these assignments from time to time, so confirm on irs.gov the day you mail. Filers living outside the US use the separate international addresses on the same page.

The tool calculates a date and a mailing location. It does not tell you whether an 83(b) is a good idea for your grant. That depends on the spread between fair market value and what you paid, the vesting schedule, and the chance of forfeiture.

It also does not cover:

• Vested stock, where no election is needed
• Standard (non-early-exercise) stock options, where 83(b) does not apply at grant
• Token and crypto grants, which raise separate valuation questions
• State filing rules, since states generally follow the federal election

If you paid fair market value for founder shares at formation, the election usually costs nothing in current tax and starts your holding period, which matters for QSBS under IRC §1202 and long-term capital gains.

Treas. Reg. §1.83-2(d) requires you to give a copy of the election to the company you perform services for (and to the transferee, if different). Send it to whoever keeps the cap table, and ask them to store it with the stock agreement.

For property transferred on or after January 1, 2016, you no longer attach a copy to your Form 1040, but keep your own copy with proof of filing: the online confirmation, or the certified mail receipt and return card. Investors' counsel will ask for it during due diligence. This page gives general information, not tax advice for your specific facts.