Businesses need to know key tax deadlines. For organizations that handle sales tax, these include quarterly filing due dates. The United States Internal Revenue Service (IRS) imposes penalties of up to 25% of the unpaid amounts for businesses that fail to pay their taxes on time.

Below, we’ll discuss quarterly sales tax due dates and other key deadlines businesses need to know.

What’s in this article?

• Quarterly sales tax due dates
  
• Income tax due dates
  
• Estimated tax payments
  
• Extension deadlines
  

Quarterly sales tax due dates

In most states, the quarterly sales tax due dates are generally as follows:

• Q1 (December 1–February 28) is due by March 20

• Q2 (March 1–May 31) is due by June 20

• Q3 (June 1–August 31) is due by September 20

• Q4 (September 1–November 30) is due by December 20

Time frames vary by state, potentially requiring payments to be made monthly, quarterly, or annually. Check with your state’s Department of Revenue (or Taxation) for the specific due dates in your jurisdiction.

Income tax due dates

Here are the typical deadlines for businesses to pay income tax:

• C corporations: The income tax return (Form 1120) is due on April 15 for C corps that follow the calendar year. For corporations operating on a fiscal year, amounts are due on the 15th day of the third month after that cycle ends.

• S corporations and partnerships: These business structures have their filings due on the 15th day of the third month following their tax year, whether they follow a calendar or fiscal year. S corps use Form 1120-S, and partnerships use Form 1065.

• Sole proprietorships: Sole proprietors report their business earnings on their tax return (Form 1040), due April 15. They use Schedule C to report profit or loss from the operation.

Estimated tax payments

Estimated tax payments are quarterly amounts that individuals and businesses make to the IRS throughout the year to cover their expected tax liability. These payments are required for sole proprietors, partners, and S corp shareholders if they anticipate owing $1,000 or more when filing their return. The same applies to C corps expecting to owe at least $500.

Who needs to make estimated tax payments?

• Self-employed individuals: If you earn income from self-employment, such as freelancing, consulting, or running a business, you are typically required to make estimated tax payments.

• Investors: If you earn substantial earnings from investments such as dividends, interest, or capital gains, you might need to make projected payments.

• Employees with side income: If you have a regular job with withholdings, you might need to make estimated payments if you earn substantial additional revenue.

When are estimated tax payments due?

The due dates for estimated tax payments are as follows:

• Q1 (January 1–March 31) payments are due by April 15

• Q2 (April 1–May 31) payments are due by June 15

• Q3 (June 1–August 31) payments are due by September 15

• Q4 (September 1–December 31) payments are due by January 15 of the following year

How to calculate estimated tax payments

• Estimate your income: Determine your expected income for the year, including all sources of revenue.

• Calculate your tax liability: Use the current tax rates and deductions to approximate your total liability for the year.

• Subtract withholding: If amounts are withheld from your paycheck or other sources, subtract this from your projected total.

• Divide by four: Divide the remaining figure by four to determine your quarterly estimated tax payment.

How to make estimated tax payments

You can make these payments online, by mail, or by phone using the Electronic Federal Tax Payment System (EFTPS). You can also use IRS Direct Pay or pay through your online IRS account.

Extension deadlines

Businesses can typically apply for extensions when filing their federal or state tax returns. Here’s what you need to know:

• Federal tax returns: Businesses can apply for a six-month extension to file their federal tax returns. They must do so by the original due date. The forms differ by entity type: C corps, S corps, and partnerships use Form 7004, while sole proprietorships use Form 4868.

• State tax returns: Extension deadlines and procedures vary, so it’s important to consult your state’s Department of Revenue for specific information.

• Sales tax returns: Check with your state’s Department of Revenue for any extension rules regarding these filings.