If your paid tax return preparer makes a major mistake, or purposely fudges the numbers, you're ultimately responsible for repaying any refund amount you didn't deserve.

A New Jersey office for the Internal Revenue Service is advising residents of a few warning signs and straight-up scams to look out for leading up to Tax Day on April 15.

"When you're talking about selecting a tax preparer, it's really important to really think about that as seriously as you would picking a doctor or a lawyer," said Special Agent Robert Glantz with the IRS Criminal Investigation Newark Field Office.

Anyone who claims they can obtain a larger refund than your last preparer, without knowing any of your financial details, is starting the whole process dishonestly, Glantz noted. You also don't want to use a preparer who bases their fee on a percentage of your tax refund.

"They're probably going to be more inclined to put things on your tax return that don't belong there," Glantz said.

References from family and friends are a good starting point when attempting to find a legitimate professional, Glantz said. The IRS website also hosts a directory of federal tax return preparers who hold professional credentials recognized by the IRS or who hold an Annual Filing Season Program Record of Completion.

You'd also be wise to make sure the person who prepares your taxes actually signs the return. Even with the signature, though, you're ultimately responsible for the submission's accuracy.

The IRS is calling!

The IRS will never threaten you, in person, over the phone, or through email, Glantz said. So any threat from someone claiming to be with the IRS should serve as a red flag.

But IRS phone scams have been targeting individuals for years because they do work from time to time.

The agency does not demand payment over the phone, or demand payment via a prepaid debit card, Glantz added.

"If you legitimately owe money to the IRS, you're going to write a check to the United States Treasury," Glantz said.

Adding to the confusion is a criminal's ability to "spoof" a number to make it look like the call is actually coming from the federal government.

According to Glantz, tax-related scams tend to ramp up this time of year, although IRS-impersonation scams are a year-round threat.