When is the 2017 tax deadline? When isn't it?

The Internal Revenue Service starts accepting tax returns on Jan. 29 and is expecting more than 155 million tax returns to be filed this year. However, the filing deadline for individual tax returns falls on Tuesday, April 17, this year. The standard deadline, April 15, falls on a Sunday and would typically be postponed to Monday, April 16 if that day didn't also happen to be Emancipation Day in Washington, D.C.

Even with the filing deadline pushed off by two days, there are still numerous deadlines for taxpayers to be aware of both before and after that date. Paul Gevertzman, certified public accountant and tax partner at Anchin, Block and Anchin in New York, suggests that sending a tax return at or before tax season's Jan. 29 kickoff date is one of the best ways to avoid having someone file a fraudulent return in your name. With more than 143 million people affected by a data breach at credit firm Equifax last year, Gevertzman says it pays to be cautious and file before a criminal does.

If they beat you to the punch, your return will be rejected and you face the onerous task of proving to the IRS that you are you," he says.

Depending on your filing status, you may have to file early anyway. March 15 is the initial filing deadline for partnerships and S-Corporations. Shomari Hearn, certified financial planner, enrolled agent and managing vice president of Palisades Hudson Financial Group in Fort Lauderdale, Fla., notes that partnerships and S-corporations don't pay taxes as entities.

"Instead, they provide their partners or shareholders with a form Schedule K-1, that provides these individuals with their share of the entity's income and deductions, which the partners/shareholders must then report on their individual income tax returns," Hearn says.

The March 15 deadline is strictly to allow time for the Schedule K-1 forms to arrive well before April 17. The latter date is still of greatest importance and still when most individuals have to actually pay their taxes. As both Gevertzman and Hearn point out, any taxpayer can seek a filing extension, but they still have to project how much federal and state tax they owe and make a payment.

"It is an extension of time to file, not to pay," Gevertzman says.

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There are some exceptions to the rule. If a tax return was rejected for any reason, taxpayers have until April 22 to submit another return with payment. Taxpayers living abroad or serving in the military get a little more leeway and have until June 15 to file their tax return.

Without those exceptions, a taxpayer has to file for an extension if they're going to submit their returns late. That leads to a completely different set of deadlines:

  • Sept. 17, S-corporation and partnership final filing deadline: Even this can be difficult to meet if you have partnerships invested in other partnerships and are held up by another partnership's filing schedule. "Imagine a tiered structure where one partnership filing right by the deadline can hold up many others from filing because they haven't yet provide the Schedule K-1s," Gevertzman says.
  • Oct. 1, estate/trust tax return final deadline: Estates and trusts are waiting on Schedule K-1 forms similar to those used by partnerships and S-Corporations, which often makes extensions necessary for similar reasons.
  • Oct. 15, personal tax return final deadline: Taxpayers should have paid all they owe in April and should still file in a timely fashion even if they can't currently pay in full. As the IRS notes, the penalty for late payment is 0.5% per month, while the penalty for late filing is 5% per month. "Many people delay or avoid filing because of inability to pay. This only makes things worse," Gevertzman says.
  • Oct. 20, resubmitted return final deadline: If you've struggled with electronic filing to this point, just give up and file a paper return.

Even those aren't the final deadlines. If a taxpayer is lucky enough to expect a refund, they have three years after their initial filing deadline to file and claim their refund. If you were supposed to file or resubmit your return, you have until April 17 or April 22, 2021 to claim the refund. If you filed for an extension, you have until Oct. 15 or 20, 2021 to file for that refund. Gevertzman suggests taking the extension anyway so you can make payments toward 2018 with the extension.

"By adding it to the extension payment it gives you a cushion in case you miscalculated on the extension amount due,"he says. "Any overpayment can get applied to the next year when the actual return is submitted."

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This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.