CHICOPEE, Mass. (WWLP) – Just 11 days to the federal tax deadline and the IRS has only received around half of the returns they expected this year.

Thanks to reduced refunds and increased liability, the final days of this tax season are going to be crunchier than usual for professionals and IRS agents working to process returns.

Only about 80 million of the 160 million expected tax returns have been filed as of the most recent weekly report from the IRS. That means a lot of people are likely filing extensions. But it’s not as easy as filling out a form and kicking back until the extended deadline in October.

“Because an extension is an extension of time to file but not an extension to pay your taxes. The taxes you owe on April 18th are due April 18th. If you’re getting a refund there’s no penalty for filing late.”

To file, you’ll need to gather any and all documents related to income and any proof of purchase or life changes that could be tax deductible or counted as a tax credit. Then, hit the software, or visit a professional, and it should be quick work. If you skip filing and end up owing back taxes, that’s when the penalties start kicking in.

If you believe you will owe taxes this year and are filing an extension you should include an estimated payment of how much you owe. But the IRS is eventually looking for a specific number. So, if you file an extension and estimate poorly they will tack on five percent of the total amount you owed per month until you have settled up.

If you don’t bother to file an extension, the fee for late filing jumps to 25 percent of what you owe.