Per Diem Rates from the U.S. General Services Administration
Search by city, state or ZIP code, or by clicking on the map. You can also use the new per diem tool to calculate trip allowances
Rates are set by fiscal year, effective October 1 each year. Find current rates in the continental United States ("CONUS Rates").
Audit Proofing Your Car Deduction
If you're self-employed, your deduction for the business use of your vehicle could slash your tax bill by hundreds of dollars! However, you can kiss this great deduction good-bye if you're audited and can't support your deduction. Without evidence to support your deduction, the IRS can disallow it.
Mileage Log
If audited, the IRS will want to see at least two things: (1) your mileage log and (2) your odometer readings for the year. These records are needed to support your deduction whether you use the actual expense method or the standard mileage rate for claiming your deduction.
Keep in mind, while you may use the standard mileage rate for claiming your mileage deduction, there are other deductions you may claim that you can add to your mileage deduction, thus increasing your overall vehicle deduction.
For example, you may the business-related portion of car loan interest and the personal property tax portion of your vehicle's registration fee (assuming you live in a state that assesses the fee based on the value of the vehicle as opposed to some other measurement, such weight). If you drive less than 100% for business purposes you will need to know your business-use percentage to allocate the portion of these items to be added to your mileage deduction amount.
Example of Mileage Log
Odometer Reading:
01/01/2021: 10,000
12/31/2021: 30,000
| Date | Destination | Business Purpose | Odometer Start | Odometer End | Miles |
|---|---|---|---|---|---|
| 01/06/2021 | John Smith client | Review contract | 10,200 | 10,230 | 30 |
| 01/015/2021 | Amy Rogers client | Discus services | 10,230 | 10,245 | 15 |
| Total 01/31/2021 | 45 |
Mileage Sampling
If you've already completed the year without tracking your mileage, you may be able to use a short-cut approach to create a record acceptable to the IRS, referred to as mileage sampling. It involves a three-month sample period. You maintain your mileage log for three consecutive months of the tax year, then use the three-month log to substantiate the business-use of your vehicle for the entire year. The IRS says you may use this three-month sample IF you can demonstrate by other evidence (such as your appointment book) that your three-month selection is representative of your use for the entire tax year.
You need the three-month sample whether you use the standard mileage rate method or the actual expense method to claim your car expense deduction. You'll need four odometer readings for the year:
- The reading on January 1 of the tax year
- The reading for the beginning of the three-month test period
- The reading at the end of the three-month test period
- The reading on December 31, the end of the calendar tax year