Starting Your Business/Keeping Records
Record keeping

Except in a few cases, the law does not require any special kind ofrecords. You may choose any record keeping system suited to your business that clearlyshows your income.

The business you are in affects the type of records you need to keepfor federal tax purposes. You should set up your record keeping system using an accountingmethod that clearly shows your income for your tax year. See Accounting Method. If you are inmore than one business, you should keep a complete and separate set of records for eachbusiness.

hotel rooms KortrijkYour record keeping system should include a summary of your businesstransactions. This summary is ordinarily made in your books (for example, accountingjournals and ledgers). Your books must show your gross income, as well as your deductionsand credits. For most small businesses, the business checkbookis the main source for entries in the business books. In addition, you must keepsupporting documents.

Recordkeeping

Important References: 

Publication 583 Starting a Business and Keeping Records