1. IRS Due Dates 
2. Deadlines on Tax Filings
3. Applying for an Extension 

Filing an S corp tax extension form is important if you're not ready to file your returns before the deadline. The IRS requires S corporations file a corporate income return annually, despite not paying corporate income tax on most types of earnings. Sometimes it might be difficult to get all the information in time to file the S corporation's return. 

You may need to file an IRS Form 7004 for an extension. Just remember that while you have an extension to file, it doesn't mean you get an extension to pay any taxes owed. Extension requests must be filed by the regular filing due date in most cases. You can only get one extension per year. If a return date falls on a weekend or legal holiday, the next business day is the date you use. 

Before filing tax returns as an S corporation, ensure your status is truly valid. Filing as the wrong status can result in significant penalties and fines. 

IRS Due Dates 

  • Single member LLCs and sole proprietorship tax returns filed on Schedule C are due on April 15. 
  • Tax returns for partnerships are due on the 15th day of the third month following the partnership's tax year. 
  • Tax returns for S corporations are due on the 15th day of the third month following the company's fiscal year-end. 
  • C corporations have tax returns due on the 15th day of the fourth month following fiscal year end. 

Depending on the type of tax return you're filing, the IRS sets different deadlines for extensions. 

Deadlines on Tax Filings

Deadlines are usually for several months after the original filing date: 

  • Six months on partnership tax filings, which includes LLCs that file as partnerships
  • Six months for C corporation and S corporation tax filings
  • Six months for sole proprietorships that are filing a Schedule C with IRS Form 1040, this includes any LLCs who are filing as sole proprietorships

For partnerships and corporations who don't follow a calendar year (Jan - Dec), you'll need to calculate your due date and then add the appropriate months of the extension. 

Applying for an Extension 

To apply for an extension, you need to follow a series of steps:   

  • Start by calculating how much tax the S corporation owes for the current tax year.
  • Next, download a copy of IRS Form 7004. Form 7004 is the required form needed to request an automatic six-month extension on S corporation filings
  • Complete IRS Form 7004 through Part II. Be sure to include all pertinent information like EIN at the top. 
  • You can Skip Part I and go to Part II where you can use "25" as the form code. This relates to IRS Form 1120S, which is the form needed for S corporation tax returns. Complete the two remaining questions in Part II. 
  • Next, fill out Part III. You can skip the first question unless the S corporation keeps its records and books outside of the United States and earns most of its income from possessions inside the United States, or is an international corporation with a US business location. 
  • Enter the tax year and estimated tax for the remaining questions. 
  • File the form with the IRS, which must be received by the original return due date. 
  • There is an option to either e-File the extension or mail to the IRS. If you can file it online, it's faster and easier. 

Official mailing addresses are listed on the IRS website. Addresses are divided based on where the business is located within the United States. There is one note, any S corporation with over $10 million in income, mails the extension to Ogden, UT, no matter where the company is located. 

Verify with your state on whether you need to file a separate extension in your state. It's important to file an extension even if you calculate you don't owe any taxes as there is a monthly penalty for filing late — which is also multiplied by how many shareholders there are. Remember that corporations typically don't have to pay taxes on their corporate form, so if you end up owing for some reason, the penalties will be even higher.

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