To be able to answer this question honestly we must define tax fraud. 



Tax fraud is defined by the Internal Revenue Service as an intentional wrongdoing, on the part of a taxpayer, with the specific purpose of evading a tax known or believed to be owing. Tax fraud requires both: 

• a tax due and owing; and
• fraudulent intent.

Have you ever heard someone say that their tax preparer “works magic”? More often than not, it’s illegal magic. The most common tax scheme that I see is adding a fictitious business to a tax return. If you need more income to qualify for a credit, add business income. If you owe taxes and need to reduce your taxable income, take a loss on your business. Let me make this clear. THIS IS TAX FRAUD.

However, avoidance of tax is not a criminal offense. Taxpayers have the right to reduce, avoid, or minimize their taxes by legitimate means. One who avoids tax does not conceal or misrepresent, but shapes and preplans events to reduce or eliminate tax liability within the parameters of the law. For example, if you itemize and you donate more for the year to increase your itemized deductions, that is completely legal.

If you think you can get away with explaining to the IRS that you simply did not know what was on your tax return or that the tax preparer did it without your knowledge, think again. When you sign the tax return you are taking full responsibility for what has been reported making you guilty as charged. 

You can report abusive tax return preparers to the IRS using Form 14157, Complaint: Tax Return Preparer. If a return preparer is suspected of filing or changing the return without the client’s consent, also file Form 14157-A, Return Preparer Fraud or Misconduct Affidavit. Forms are available on IRS.gov. 

A tax fraud offense may result in both civil and criminal penalties. Restitution may be ordered in criminal tax cases pursuant to a plea agreement or a conviction under Title 18 U.S.C. and may be required as a condition of probation. 25.1.1.2.4 (01-23-2014)

So, did you inflate your income or expenses on your tax return to create a more favorable outcome? Or turn a blind eye to your preparer inflating your refund because you liked the bottom line? If so, you are guilty of tax fraud. 

https://www.irs.gov/irm/part25/irm_25-001-001#idm140540698138736

www.irs.gov