Congressional leaders who initially promised to make taxes so simple you could file them on a postcard instead produced a tax overhaul that makes the U.S. tax system even more of a head-spinner.

The law signed by President Donald Trump in December adds new complexity and even takes a swipe at people who pay to let software or a tax professional figure out the mess for them. The deduction for tax-prep expenses is history.

But why pay for help with your taxes? Maybe you can join the 50 million Americans who get theirs done for free, thanks to a program offered by the Internal Revenue Service.

IRS Free File is exactly what the name says

The IRS says 70 percent of U.S. taxpayers qualify for its Free File service, which allows you to have your taxes completed at no cost. (Or as the tax agency's website puts it, "for less than a penny.") According to the IRS, Free File has saved Americans $1.5 billion in filing fees since its launch in 2003.

Here's how it works: If your income is $64,000 or less, you file using a free version of popular, commercial tax software such as TurboTax, H&R Block or Jackson Hewitt.

What if you earn more than $64,000? The free software isn't available to you, but if you're willing to try tackling an old-fashioned tax return on your own, you can use "Free File Fillable Forms." (Just try to say that five times fast!)

Note that while Free File is free, there can be related charges, such as a credit card fee if you use plastic to pay any taxes you owe, or a charge to file your state taxes with the same commercial tax-prep service.

NEXT: How Free File software works.