For Businesses
Income
Gross receipts from sales or services
Sales records
Returns and allowances
Business checking/savings account interest (1099-INT or statement)
Other income
Cost of Goods Sold
Inventory
Total dollar amount of beginning inventory
Inventory purchases
Total dollar amount of ending inventory
Items removed
Materials and Supplies
Expenses
Advertising
Phones (landline, fax or cell phones related to business)
Computer & internet expenses
Transportation and travel expenses
Local transportation
Business trip (mileage) log
Contemporaneous log or receipts for public transportation, parking, and tolls
Travel away from home
Airfare or mileage/actual expense if drove
Hotel
Meals, tips
Taxi, Uber, tips
Internet connection (hotel, Internet café etc.)
Other
Commissions paid to subcontractors
File Form 1099-MISC and 1096 as necessary
Depreciation
Cost and first date of business use of assets
Records relating to personal use of assets
Sales price and disposition date of any assets sold
Business insurance
Casualty loss insurance
Errors and omissions
Other
Interest expense
Mortgage interest on building owned by business
Business loan interest
Investment expense and interest
Professional fees
Lawyers, accountants, and consultants
Office supplies
Pens, paper, staples, glue, stickers, and other consumables, etc.
Rent expense
Office space rent
Business-use vehicle lease expense
Other
In-Home Office
Square footage of office space
Total square footage of home
Hours of use, if operating an in home daycare
Mortgage interest or rent paid
Homeowner's or renters' insurance
Utilities
Cost of home, separate improvements and first date of business use
Wages paid to employees
Form W-2 and W-3
Federal and state payroll returns (Form 940, Form 941, etc.)
Employee benefit expenses
Contractors
Form 1099-MISc
Form 1096
Other expenses
Repairs, maintenance of office facility, computers, etc.
Estimated tax payments made
Other business related expenses
Health insurance
Premiums paid to cover the sole-proprietor and family
Premiums paid on behalf of partners and S corporation shareholders
Information on spouse's employer provided insurance