Republicans wants to make filing taxes as easy as mailing a postcard - but there's a flaw in the plan

Post card tax returns are all the rage in the Republican party, but they may have a more complicated impact than they seem.

Treasury Secretary Steven Mnuchin said during an event for The Hill on Wednesday that Trump's huge tax plan's goal is to allow Americans to "do their taxes on a large post card."

This follows years of Republicans from Paul Ryan to Ted Cruz to Ways and Mean Committee Chair Rep. Kevin Brady advocating for a similar post card return.

While the idea of a simple form on which to file your taxes sounds great, it may actually more intricate than it first appears.

Roberton Williams at the Urban Institute's Tax Policy Center wrote in June 2016, after Ryan's Better Way plan released an example of the post card tax return, that the form seems to require only a few numbers but in fact could force you to do more calculations than you'd think.

"Like every promise of a one-page tax return, this one is misleading at best," Williams wrote. "Sure, you can create a simple return, but only by moving many calculations to separate forms or worksheets. Ryan and the House Republicans deserve credit for their proposal to simplify the tax code, but they aren't making it as simple as their one-page return makes it seem."

For instance, Williams noted that the first line of the Ryan post card calls for you to write your "wage and compensation income." For most people this would be one number from a W-2. But if you've had multiple employers, this would require you to add them together - most likely using a work sheet.

Other seemingly simple tasks on the post card, such as "subtract child credit," become more complicated if a filer has joint custody of a child or other circumstances, requiring additional paperwork to compute.

Also the post card Republicans propose, Williams notes, does not include various other aspects like unemployment benefits and 401(k) contribution, unless those become tax free.

So while the post card looks like a breeze, it could take longer than it appears.