This calendar assumes a Delaware C corporation that uses the calendar year as its tax year, as nearly all startups do. When a date falls on a weekend or legal holiday, the deadline generally moves to the next business day.
| When | What is due | Who it applies to |
|---|---|---|
| January 31 | W-2s to employees and the Social Security Administration; 1099-NECs to contractors and the IRS; Form 940; Form 941 for the fourth quarter | Companies with payroll or contractors |
| March 1 | Delaware annual report and franchise tax for the prior year | Every Delaware corporation |
| April 15 | Form 1120 federal income tax return, or Form 7004 to extend it six months; state returns where registered | Every C corporation |
| April 15, June 15, September 15, December 15 | Federal estimated income tax payments | Companies that expect to owe income tax |
| April 30, July 31, October 31 | Form 941 for the first three quarters | Companies with payroll |
| June 1, September 1, December 1 | Delaware franchise tax installments | Companies whose Delaware tax is $5,000 or more |
| Anniversary of formation | Registered agent renewal | Every Delaware corporation |
| Set by each state | Annual reports and minimum taxes where registered; sales tax returns where you collect | Registered companies |
| Within 15 days of the first sale | Form D with the SEC, and state notices | Companies raising money |
| Every 12 months while granting options | A new 409A valuation | Companies with stock options |
March 1 in Delaware
The annual report lists the company's address, its directors and one officer, along with the figures the franchise tax is calculated from, and it is filed online with the tax and a $50 fee. The first report is due on March 1 of the year after the company is formed. Filing late costs a $200 penalty plus interest of 1.5 percent a month on unpaid tax, and a company that does not pay loses its good standing. The next chapter explains how the tax is calculated and how to avoid overpaying.
April 15 for the IRS
A C corporation files Form 1120 every year, even with no revenue and even at a loss. The return is also where startups claim the research and development tax credit, and a qualified small business can apply up to $500,000 a year of that credit against its payroll taxes, which is valuable before the company has any income tax to offset. An extension extends the time to file, not to pay, though a company with losses usually has nothing to pay.
January 31 for workers
Companies send Form 1099-NEC to most unincorporated contractors paid more than a threshold during the year. The threshold was $600 for payments through 2025 and rose to $2,000 for payments made in 2026 and later. Collect a Form W-9 from every contractor before you pay them, so you have their tax ID when January comes.
Things with no fixed date
Some obligations recur without a date. The board approves each option grant when it is made, at the current 409A price. Delaware requires an annual meeting to elect directors, but startups almost always have stockholders act by written consent instead. The cap table needs updating whenever shares, options, SAFEs or notes are issued, exercised, transferred, repurchased or canceled. And once the company carries insurance, its policies renew each year.