ITG FAQ #8 Answer-Are employers required to withhold taxes from their employees’ wages?
Yes. Employers are required to withhold and pay employment taxes. Employment taxes represent the income tax, social security and Medicare taxes (also known as FICA, Federal Insurance Contributions Act taxes) withheld from the wages of an employee plus the employer’s share of social security taxes and federal unemployment (FUTA) taxes, when applicable. The withheld (employee’s) portion of employment taxes is referred to as "trust fund" taxes.