2015 Tax Tips: Avoid Frequent Mistakes on Tax Returns

Here's the biggest source of mistakes when filing your taxes.

— -- Having a sense of organization may help avoid common mistakes when filing tax returns.

"I think the biggest mistake people make is a failure to plan,” said Tom Wheelwright, the CEO and founder of CPA firm Provision.

Wheelwright recommends organizing important documents and considering hiring someone to do your tax paperwork.

IRS spokesman Eric Smith recommends filing your taxes online.

"Really, the mistakes of filing are often much more related to paper returns,” said Smith.

Smith adds that taxpayers frequently forget to attach their W2s and other documents when filing by mail.

TurboTax vice president Bob Meighan says one of the easiest ways to avoid mistakes is to simply check the numbers.

"People need to double-check their Social Security number, number one,” Meighan said. "Number two: check the Social Security number of your dependents, cause we often forget what our children's Social Security numbers are ... because if they're not correct, your return will get rejected."

Another pro tip: be sure to proofread your tax return for any typos.