Just like not being tardy for the party, taxpayers shouldn't be filing their taxes late because latecomers are subject to penalties.
These penalties are monetary and fall under either the "failure to file" or "failure to pay" category, or both, the IRS says.
Here's what you need to know about late filing and payment penalties:
According to the IRS, failure-to-file penalties are usually more than failure-to-pay penalties.
The total late-filing penalty is typically 5 percent of the tax owed for each month or part of the month that your return is late. The IRS can charge you this late-filing penalty for up to five months or up to 25 percent of your unpaid taxes.
If you're late to file by more than 60 days after the due date (or extended due date), then the minimum penalty is either $135 or 100 percent of the unpaid tax.
For people who fail to pay the full amount owed by the due date, they're penalized by having to pay 0.5 percent of the tax owed each month or part of a month that the tax remains unpaid. Like the failure-to-file penalty, the maximum is 25 percent of your unpaid taxes.
On the other hand, if you request an extension before the filing deadline and have paid at least 90 percent of your actual tax liability before April 15, then you won't be subject to any failure-to-pay penalties -- unless you don't pay the remaining balance by the extended due date.
The IRS exercises some leniency and won't make you pay the penalties if you can show that your failure to file or pay on time was based on a reasonable cause and not just plain neglect or laziness. If you foresee trouble paying the full amount due on time, consider negotiating an installment agreement with the IRS to pay off back taxes.
To avoid these penalties, be sure to either get an extension to file or estimate the amount of taxes you owe and pay by the deadline. Even if you accidently overpay, the IRS will credit your overpayment.
If you need more help, contact an experienced tax attorney in your area to figure out your legal options.
Editor's Note, April 12, 2016: This post was first published in March 2014. It has since been updated.