Partnerships (Form 1065) can find further e-file information for partnerships using the MeF platform on IRS.gov at Modernized e-File (MeF) for partnerships or they may contact the e-help Desk at 866-255-0654. As of November 1, 2008, the 1065 Modernized e-File Mailbox is no longer active. Corporate taxpayers (Forms 1120, 1120-S, 1120-F) may contact the e-help Desk at 866-255-0654. Tax-exempt organizations can find further e-file information on IRS.gov at E-file for charities and nonprofits. Taxpayers with account or tax law questions may call 800-829-4933. Tax practitioners with account or tax law questions may call 800-829-8374. Software developers and vendors may contact the e-help Desk at 866-255-0654 with questions about e-filing.