In August, 2007, final regulations (T.D. 9356) (PDF) were issued requiring disregarded LLCs to be treated as the taxpayer for certain excise taxes accruing on or after January 1, 2008 and employment taxes accruing on or after January 1, 2009. Single-member disregarded LLCs will continue to be disregarded for other federal tax purposes.
A single-member LLC that is classified as a disregarded entity for income tax purposes is treated as a separate entity for purposes of employment tax and certain excise taxes. For wages paid after January 1, 2009, the single-member LLC is required to use its name and employer identification number (EIN) for reporting and payment of employment taxes. A single-member LLC is also required to use its name and EIN to register for excise tax activities on Form 637; pay and report excise taxes reported on Forms 720, 730, 2290, and 11-C; and claim any refunds, credits and payments on Form 8849. See the employment and excise tax returns for more information