By Lynne Adkins

PHILADELPHIA (CBS) — Tuesday is the deadline to file your taxes. Taxpayers were given three extra days because April 15 fell on a Saturday and Monday was a holiday in the nation’s capital. Unfortunately, thousands will try to file only to find they’ve been hacked.

If your tax return is rejected because someone has already received a refund under your social security number, act quickly. Nick Crocetti, Managing Director at CBIZ in Plymouth Meeting, says the IRS will contact you in writing if there’s a problem.

“Respond to that letter immediately, report the identity theft to the Internal Revenue Service in a formal matter,” Crocetti said. “There’s a form called 14039 that will start and keep the process going with Internal Revenue Service so they can investigate and authenticate your personal return.”

Contact one of the reporting services, file a police report and call your CPA or tax attorney. You’ll need help to clear this up as it could take several months.