Topics What can be deducted How much can be deducted When to deduct Not-for-profit activities Useful Items Publication 334  Tax Guide for Small Business 463  Travel, Entertainment, Gift, and Car Expenses 525  Taxable and Nontaxable Income 529  Miscellaneous Deductions 536  Net Operating Losses 538  Accounting Periods and Methods 542  Corporations 547  Casualties, Disasters, and Thefts (Business and Nonbusiness) 587  Business Use of Your Home(Including Use by Day-Care Providers) 925  Passive Activity and At-Risk Rules 936  Home Mortgage InterestDeduction 946  How To Depreciate Property Form (and Instructions) Sch A (Form 1040)  Itemized Deductions 5213  Election To PostponeDetermination as To Whether the Presumption Applies That anActivity Is Engaged in for Profit