If you're using a tax professional, expect them to be busy as that April 17 deadlines approaches.
"As things come in, we put them in a queue, first in first out," Davidoff said. "You'll get more attention from your tax preparer if you get it in in March than if you get it in in April."
In addition, rushing last's year filing could leave you less tax-informed about this year, said Brian Thompson, president of the National Society of Accountants. (This year there's even more to know, of course, thanks to the massive overhaul to the tax code).
"When I work with clients, I'm also planning with them for 2018," Thompson said. "It's the time of the year they're in our office."
If you need another incentive, remember: The sooner you file, the sooner that return will be in your back account.
"The longer you go without it," McBride said, "the longer you're giving the government an interest-free loan."