To support deductions for business travel and entertainment (T&E), estimating expenses is not permitted. Instead, you need to record the following:
The amount of the expenditure.
The time and place of the travel and entertainment.
The business purpose of the expense.
The business relationship with the person entertained.
The cost of entertainment is only 50% deductible, in most cases. To qualify, entertainment can be directly related to business: you can talk business over a meal. Alternatively, the entertainment can directly precede or follow a bona fide business discussion.
Insight: When you travel away from home on business, the cost of a meal alone or with someone else will qualify as a business meal and merit a 50% deduction. All travel and entertainment should be recorded in a log at or near the time it occurs. Except for expenditures for lodging and transportation, receipts are not required for expenses up to $75.