2024 Startup Tax Deadlines for C-Corps

Note: The federal tax deadline in 2024 falls on April 15. The federal extension deadline for 2024 is October 15. When the tax deadline is on weekend or holiday, the deadline is moved to the next business day.

THE 8 MOST IMPORTANT STARTUP TAX DEADLINES

It’s important for founders to remember that even early-stage, just founded companies can have compliance and regulatory filing requirements. And it’s critical to keep your company in compliance so that you’re ready for a venture capital term sheet or M&A due diligence. You want to be make sure that your financials are in good shape and won’t delay that transaction. Plus any regulatory or compliance issues can generate penalties and paperwork – which are distractions you don’t need when you’re building a business.

To help you stay on track, here are the most important compliance deadlinesfor all small businesses, and startups in particular:

• W2s to employees
• 1099s to all contractors - important for all businesses!!!
• Delaware Franchise Fee
• State Franchise Fees
• Federal & State Returns/Filings
• R&D Credit and Related Studies
• Municipal or City Filings
• Sales Tax

That’s a lot to remember, but keeping your startup compliant with taxes and fees is cruciall to your success.

IMPORTANT DATES AND TAX DEADLINES FOR 2024

We have a more complete list above, but the most important corporate tax deadline for businesses in 2024 is the April 15th federal and state tax due date. C corporations also have estimated quarterly taxes due on April 15th, June 15th and September 15th for businesses and corporations. C-corps can file an extension with the IRS Form 7004.

Remember, even unprofitable startups need to follow these deadlines. The federal (and state) governments require filings even if your company has a loss.

What is the 2024 Form 1120 Due Date?

The due date for filing Form 1120, the corporate income tax return, for most US corporations is April 15th, 2024. Corporations can also request an extension to file their Form 1120 until October 15th, 2024 by submitting Form 7004 to the Internal Revenue Service (IRS) by the original due date. The IRS is responsible for enforcing federal income tax laws and administering the tax system in the US.

When are C-Corporation Taxes Due?

C-Corp taxes are due on the 15th of April, which is the deadline for filing the C Corp Form 1120 Tax Return. However, it is important to note that this deadline can be extended to October 15th if an extension is filed. Some years, such as 2024 are delayed a few days, in this case, to April 18th. 

When are Quarterly Business Tax Payments Due?

For businesses generating taxable income, quarterly estimated tax payments are generally due for businesses four times a year:

• First Installment: April 15
• Second Installment: June 15
• Third Installment: September 15
• Fourth Installment: January 15 (following year)

Note that the actual date may move slightly based on Federal holidays and weekends, and that businesses with different tax fiscal year ends may have different dates. Additionally, state and local governments may be different, so always work with a qualified tax CPA.

Federal Tax Deadlines in 2024

The above calendar shows the most important Federal Tax deadlines for 2023 (it also includes some dates for Delaware C-Corps, our CPA firm’s particular client focus). The most important Federal tax deadlines to focus on for C-Corps include sending W2s to employees and 1099s to contractors, the Federal & State Returns/Filings, R&D Credits and other tax credit deadlines.

When is the last day for a startup or a Delaware C-Corp to do taxes?

The last day for a startup to file taxes is the due date for filing a Form 1120, which is the tax return form used by C-corporations (which most startups should be) to report their income, gains, losses, deductions, and credits to the (IRS), is generally the 15th day of the fourth month following the end of the corporation’s tax year. This is typically April 15th. For example, if a C-corporation has a calendar year tax year (January 1 to December 31), the due date for its Form 1120 tax return would be April 15. If a C-corporation has a fiscal year tax year (a 12-month period ending on the last day of any month except December), the due date for its Form 1120 tax return would be the 15th day of the fourth month following the end of the fiscal year.

If the due date for filing a tax return falls on a Saturday, Sunday, or legal holiday, the due date is moved to the next business day. This means that if April 15 falls on a weekend or legal holiday, the due date for filing the tax return would be the next business day.

If a C-corporation is unable to file its Form 1120 tax return by the due date, it can request an extension of time to file. To obtain an extension, the corporation must file Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns, by the original due date of the return. The extension will generally allow the corporation to file its tax return up to six months after the original due date.

When is the last day to file taxes in 2024 for tax year 2023?

The last day to file taxes in 2024 for C-Corporation (C-Corps) for the tax year 2023 is April 15th, which can be extended to October 15th. Additionally, there are March, June, Sept and December Delaware Franchise estimated payments that should be paid and filed for companies reporting profits; talk to your tax CPA to see if you need to file anything on these dates.

When are C-Corp taxes due with an extension?

An estimate of your payment is due on April 15, 2024. The last day that you can extend C-Corp tax filings until in 2024 will be October 15, 2024 (for the fiscal year ending December 31, 2023). Again, you have to file the extension by the original due date of April 15, 20243. Also note that you should pay an estimate of your 2023 amount due before April 15, or else you may face penaltise and interest.

On average, one to three of our clients are acquired every month, and we what questions that the accounting firms at big, public companies are going to ask (you can access our free due diligence checklist here). Compliance is a big one! Don’t let a life-changing transaction get sidetracked by these types of issues. Of course, we recommend working with an experienced CPA like Kruze - talk to us now.

Last Year's Tax Deadlines For C-Corp Startups

2023 startup tax deadlines are supplied for reference purposes only, and should not be used when making decisions in 2024 or beyond. Always consult your tax professional, and see our disclaimer below.

• JAN 31: Send 1099s to Contractors. Send W2s to employees. 1099-MISC for nonemployee compensation must also be e-filed to IRS on this date.
• JAN 31: File Form 8809 for a 30-day extension to file W2s and 1099-MISC for nonemployee compensation.
• JAN 31: Send 1095-B and 1095-C forms to Employees.
• JAN 31: Claim R&D Tax Credits on Form 941, and file annual Federal Unemployment Tax Act (FUTA) return on Form 940.
• MAR 1: IRS ACA Compliance 1094-B, 1095-B, 1094-C and 1095-C filings are due (if paper-filing, due MAR 31 if eFiling). File Form 8809 for a 30-day extension.
• MAR 1: Delaware Annual Franchise Report filing deadline: Pay a min. of $400, +more if you have significant funding. You can estimate this franchise tax using our Delaware Franchise Tax Calculator.
• MAR 2: IRS 30-day automatic extension: provide Form 1095-B and Form 1095-C to Employees.
• MAR 31: IRS ACA Compliance 1094-B, 1095-B, 1094-C and 1095-C filings are due (eFile).
• MAR 31: 1099s and W2s must be e-filed with the IRS by this due date.
• APR 18*: C Corp Form 1120 Tax Return due. The Federal Form 1120 is the U.S. Corporation Income Tax Return, which the IRS has companies use to report their income, losses, credits, etc., and to figure the income tax liability of the corporation. Can extend the deadline to OCT 16*.
• APR 18*: File the R&D Tax Credit Form 6765 with your tax return. Can extend to OCT 16*. We strongly recommend working with a qualified CPA to prepare this form in conjunction with your Form 1120 if you are a high-growth startup – if your company is going to be acquired by a major technology company, that company’s CFO will use a strong tax team to do due diligence on this.
• APR 18*: Federal Quarterly Estimated Tax 1st installment
• APR 18*: Due date for making contributions to individual retirement accounts for 2022 (Employee Benefits)
• APR 30: Claim R&D Tax Credits on Form 941.
• JUN 1: Delaware Quarterly Estimated Franchise Tax, Pay 40% of estimated annual amount (if annual amount expected to exceed $5,000)
• JUN 15: Federal Quarterly Estimated Tax 2nd installment
• JUL 31: Claim R&D Tax Credits on Form 941.
• SEP 1: Delaware Quarterly Estimated Franchise Tax. Pay 20% of estimated annual amount (if annual amount expected to exceed $5,000).
• SEP 15: Federal Quarterly Estimated Tax 3rd installment
• OCT 16*: C Corp Form 1120 Tax Return final due date if extension was filed.
• OCT 31*: Claim your Research and Development Tax Credits on Form 941.
• DEC 1: Delaware Quarterly Estimated Franchise Tax. Pay 20% of estimated annual amount (if annual amount expected to exceed $5,000).
• DEC 15: Federal Quarterly Estimated Tax 4th installment