TaxBizPro, LLC posted on August 17, 2009 17:00

Generally, you cannot deduct amounts that you approximate or estimate. You should keep proper records to prove your expenses or have sufficient evidence that will support your own statement. You must generally prepare a written record for it to be considered Proper. This is because written evidence is more reliable than oral evidence alone. However, if you prepare a record on a computer, it is considered a proper record.
What Are Proper Records? You should keep the proof you need in a log, account book, diary, statement of expense, or similar record. You should also keep documentary evidence that, together with your record, will support each element of an expense.You generally must have documentary evidence, such as receipts, canceled checks, or bills, to support your expenses.
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