A scheme circulating on social media is encouraging Americans to claim fraudulent tax refunds by adding fake W-2s on their tax returns, the Internal Revenue Service recently warned.

Online scammers are telling taxpayers to make up fictitious income and substantial withholdings and then to enter the figures into tax-filing software to generate larger refunds, according to the IRS.

But taxpayers caught up in this trap could face financial and criminal penalties if they are caught, the IRS and experts warned.

“There are lots of potential penalties in the tax law for both intentional and unintentional errors,” Annette Nellen, CPA and professor at San Jose State University MST Program, told Yahoo Finance. “Certainly reporting a made up deduction on the return shows intent and more severe penalties can apply such as for fraud.”

One of the recommendations by these scammers include putting down an income amount that is just low enough to trigger eligibility for the Earned Income Credit. Other fraudsters are encouraging taxpayers to search online for the legitimate federal identification numbers of employers to push made-up W-2s through the system, according to one tax expert.

“Normally the thieves report a relatively small amount of income but a large amount of federal withholding with the goal of not just maximizing a refund from withholding, but also for generating income tax credits for such items as the Earned Income Tax Credit (EITC) and education credits,” Tom O’Saben, an enrolled agent and director of tax content and government relations at National Association of Tax Professionals, wrote to Yahoo Finance.

The IRS reminded taxpayers that it has partnered with the Security Summit as well as the Social Security Administration to verify W-2 forms. The Security Summit is composed of the IRS, 42 state tax agencies, and the tax community — including tax preparation firms, software developers, payroll and tax financial product processors, tax professional organizations and financial institutions.