Can I write off gas expenses if I didn't keep track on my miles?

[morg2019]

I'm self-employed and use my truck for business.  I didn't track my miles, but I was hoping to write off my gas expenses.  I am using the downloaded turbo tax edition. In the vehicle expense section, the first thing it asks is "Did you document the miles you drove for this business?" I selected "No, I didnt".   Then next, "Did you track the miles you drove for personal stuff" I selected "No, i didn't". Click continue, and then it asks how I want to enter my mileage. Since I didn't keep track, can I bypass this? Without entering in miles, I cant continue to any other expenses, such as the gas.  

[MonikaK1]

Unless your vehicle is used 100% for business - e.g., kept at a business location and not used for commuting to and from work - you need to have a method in place to track the business use of the car, if using the mileage method of deducting expenses, and to track both business and personal use, if you use the actual expense and depreciation method of claiming expenses.

As you have found, you will need to have come up with some method of tracking business and personal use of the vehicle in order to claim actual expenses in TurboTax.

From IRS Topic 510:

"If you use your car only for business purposes, you may deduct its entire cost of ownership and operation (subject to limits discussed later). However, if you use the car for both business and personal purposes, you may deduct only the cost of its business use.

You can generally figure the amount of your deductible car expense by using one of two methods: the standard mileage rate method or the actual expense method. If you qualify to use both methods, you may want to figure your deduction both ways before choosing a method to see which one gives you a larger deduction.

The law requires that you substantiate your expenses by adequate records or by sufficient evidence to support your own statement. For further information on recordkeeping, refer to Topic no. 305."

If you're in business, there's not a required method of bookkeeping you must use. However, you must use a method that clearly and accurately reflects your gross income and expenses. The records should substantiate both your income and expenses. If you have employees, you must keep all your employment tax records for at least 4 years after the tax becomes due or is paid, whichever is later.

Please see this TurboTax article and IRS Publication 463 for more information on deducting business use of vehicles.