The only prep work that differs for businesses is the type of documents that you will collect. For businesses, you need to keep detailed records of all revenue and expenses with dates and amounts and document the purpose behind your travel and entertainment expenses. Documents you will want to have on hand for a business audit include all receipts organized by date with a note of what was purchased, bills with the type of service and date, canceled checks, any legal papers, loan agreements, logs or diaries, travel ticket stubs, medical & dental records, theft or loss records, employment records, and Schedule K-1's, along with bank and financial statements. Keeping records of your tax-related documents for two to six years is usually long enough to satisfy small business tax requirements.