IRS Phone Numbers: Reach the Right Department The main IRS individual taxpayer phone number is 800-829-1040, generally open Monday through Friday from 7 a.m. to 7 p.m. IRS Form 945: Annual Nonpayroll Withholding Guide IRS Form 945 is the annual return used to report federal income tax withheld from nonpayroll payments, including backup withholding IRS Form 990-N: Nonprofit e-Postcard Filing Guide IRS Form 990-N is the annual electronic notice—often called the e-Postcard—generally available to small tax-exempt organizations whose gross receipts are IRS Extension Forms: 4868, 7004 and Other Filers The correct IRS extension form depends on the return: individuals generally use Form 4868, businesses often use Form 7004, exempt IRS Form 5329: Retirement Account Additional Taxes IRS Form 5329 reports additional taxes involving IRAs, qualified retirement plans, Coverdell ESAs, ABLE accounts, qualified tuition programs, Archer MSAs, IRS Form 1065: Partnership Return Filing Guide IRS Form 1065 is the annual information return a domestic partnership generally files to report income, deductions, gains, losses, credits, IRS Schedule 1: Additional Income and Adjustments IRS Schedule 1 accompanies Form 1040 or 1040-SR to report types of additional income not entered directly on the main IRS Form SS-4: How to Apply for an EIN? IRS Form SS-4 applies for an Employer Identification Number, the federal tax ID used to identify a business, estate, trust, EFTPS Guide 2026: Enrollment, Payments and Deadlines EFTPS is the U.S. Treasury’s free Electronic Federal Tax Payment System for federal tax payments; in 2026 it remains available IRS Form 14039: Identity Theft Affidavit Guide The February 2026 revision of IRS Form 14039 reports tax-related identity theft or a current risk that a taxpayer’s information 1 2 3 … 205 Next »