IRS Definition - Abusive Return Preparer

A Return Preparer is defined as any person (including a partnership or corporation) who prepares for compensation all or a substantial portion of a tax return or claim for refund under the income tax provisions of the Internal Revenue Code.

Return Preparer Fraud generally involves the orchestrated preparation and filing of false income tax returns (in either paper or electronic form) by unscrupulous preparers who may claim, for example:

inflated personal or business expenses,
false deductions, or
unallowable credits or excessive exemptions, fraudulent tax credits, such as the Earned Income Tax Credit (EITC).
The preparers' clients may or may not have knowledge of the false expenses, deductions, exemptions and/or credits shown on their tax returns.