You may deduct 80%. IRS Publication 463 Travel, Gift, and Car Expenses, page 16 states:
In general, you can deduct only 50% of your business-related meal expenses, unless an exception applies. (If you are subject to the Department of Transportation's “hours of service” limits, you can deduct 80% of your business-related meal expenses.)
The 50% limit applies to employees or their employers, and to self-employed persons (including independent contractors) or their clients, depending on whether the expenses are reimbursed.
Examples of meals might include:
- Meals while traveling away from home (whether eating alone or with others) on business, or
- Meal at a business convention or business league meeting.