Best Practices for Tracking Business Expenses for Mobile Sales Teams

When an outside sales rep uses their personal vehicle for their work-related driving (attending client meetings, for example), their employer often reimburses them for those business miles. Tracking business expenses for each trip keeps the reimbursement tax-free, as long as the records meet requirements set by the IRS.

Today, we’ll walk you through best practices for tracking business expenses for your mobile sales team, from what method you choose to the records you keep. 

Choose a Reimbursement Method for Your Sales Team

Your reimbursement method determines what mobile sales representatives receive and what records they maintain while tracking business expenses, so choose wisely. 

Cents-Per-Mile

The IRS publishes a standard mileage rate for each business year. That rate gets calculated using national average costs associated with owning and operating a vehicle, including depreciation and fuel costs. As of fall 2026, the IRS rate is 76 cents per mile.

Mobile employees record their business mileage, and each mile gets multiplied by the agreed-upon cents-per-mile rate to find the amount for reimbursement, which keeps tracking business expenses simple for reps. 

What About a Custom Cents-Per-Mile Rate? 

Most companies use the IRS rate for reimbursement (for simplicity’s sake if nothing else), but it’s not mandatory that you reimburse employees at the IRS mileage rate. 

Businesses that want to reimburse at a rate that more closely aligns with vehicle ownership costs in their specific regional area are permitted to do so. However, you’ll need to keep a couple things in mind. 

If a business reimburses employees using a rate higher than the one set by the IRS, then the excess is considered taxable wages, because reimbursements are only tax-free up to the IRS rate. 

If your business makes the choice not to reimburse at the IRS rate, it’s generally a good idea to reimburse at a lower rate than the IRS standard mileage rate, instead of a higher one.

That being said, though, you still need a close eye on the custom rate you set. If your workers make at or near minimum wage, make sure the rate you choose doesn’t accidentally trigger the Federal Labor States Act’s (FLSA) “kickback rule.” 

The FLSA has a narrow exception for reimbursements, which governs money ‘kicked back’ to the employer in the form of underreimbursed mileage expenses. If the value of these so-called kickbacks pushes the salary of the worker under minimum wage, a wage and hour issue is created. 

Trust us, it’s less confusing than it sounds. But to help cut through some of that confusion, CompanyMileage’s free rate calculator, helps businesses find a custom mileage rate based on gas prices in their area. 

Fixed and Variable Rate (FAVR)

FAVR splits every reimbursement payment into two parts:

1. A fixed monthly amount that covers depreciation, taxes, insurance premiums, and registration and licensing fees
2. The variable day-to-day costs that go up as mileage driven does, including fuel, regular maintenance, and repairs 

Both of these amounts reflect the costs where each employee lives and works. So a rep in a high-cost metro area could receive more than one who lives in a lower-cost region who drove for the same number of miles.

For businesses to meet the requirements for FAVR, the IRS states that:

• Allowances must cover at least 5 employees at all times during the calendar year
• Annual business mileage used to calculate the FAVR allowance cannot be less than 6,250 miles
• Companies must log a minimum of 5,000 miles annually to qualify for a FAVR program
• Employee vehicles meet the company vehicle standard 

FAVR also requires mileage paperwork. In this case, tracking business expenses for reimbursement includes each employee’s business mileage (with commuting mileage deducted), and documentation regarding each rep’s vehicle and insurance coverage. 

Flat Car Allowance

A car allowance pays eligible mobile employees a fixed amount of money on a set schedule to cover the cost of using their personal vehicles for work. That payment covers the ordinary expenses of owning a vehicle: maintenance, wear and tear, insurance, fuel, and depreciation. 

The allowance amount gets set by a company policy (often by role, seniority, or territory) and paid on a regular schedule.

Allowances are generally processed as wages and appear on an employee’s paycheck and follow normal payroll procedures and withholding. 

How to Pick a Tracking Method 

Weigh these three factors:

• Mileage differences between representatives. If some of your team members drive far more than others, using a per-mile (either cents-per-mile or FAVR) ensures that reps get reimbursed for the miles they actually drive.
• Cost differences by region. If you have sales reps spread across the country (or even multiple countries), then each rep will probably have different fuel and insurance costs associated with using their personal vehicle for work. In those cases, FAVR accounts for those costs.
• Administrative workload. The standard rate method requires an IRS-compliant mileage log to keep reimbursements accountable. FAVR requires mileage logs plus vehicle and cost data. Car allowances require the least record-keeping, but without logs, the full amount would get treated as taxable income. 

Define Which Sales Trips Qualify for Reimbursement

Some trips employees take in their personal vehicles over the course of their workday qualify for reimbursement; Others don’t. You and your team need to know the difference when it comes to tracking business expenses. 

What Trips Qualify?

Reimbursable trips are ones that mobile employees make as part of executing their normal job duties, such as:

• Client visits
• Prospect meetings
• Trade shows, conferences, and industry events
• Travel between your business’ office and a customer site
• Travel from one client location to another
• Pickups of samples, supplies, or materials for a client

What Doesn’t Qualify? 

Trips unrelated to work, such as errands, or a quick stop for lunch, are considered personal travel, and therefore not eligible for reimbursement. And before you ask, yes, commuting is considered a personal expense. 

The IRS defines a commute as travel between an employee’s home to their regular office or another business location. Even if a rep takes a sales call during that drive, it’s still not eligible for reimbursement.

IRS Publication 463 and Revenue Ruling 99-7 do, however, recognize two exceptions that apply to field reps:

• Home office as principal place of business. If a rep’s home office is their principal place of business, then trips between their home and other work-related locations does count as business mileage.
• Temporary work locations. If a rep has a regular office, then traveling from their home to a temporary work location, such as a client site, qualifies as business mileage. 

How Do You Log Multi-Stop Days? 

A single sales day often includes several client stops. Tell your reps to handle tracking business expenses by logging each leg as its own entry, from one address to the next. 

A day with three client visits that starts and ends at the office, for example, would produce four entries.

Personal stops between client visits, like running a quick errand, should not count toward the business mileage total. Reps log the distance from one client to the next, leaving out the extra miles they drove for the personal stop. 

Separate entries for each leg tie each entry to one trip and one specific business purpose, making those multi-stop days easier to verify. 

Write the Rules Into Your Policy 

As we always say, your reimbursement policies and workflows around tracking business expenses won’t do much good if your mobile workforce doesn’t know what they are! 

You have to have a written mileage policy and you have to make sure it’s completely available and accessible to the people who need it. 

Collect the Right Data 

Mileage reimbursements are separate from wages and therefore not taxable – provided, of course, that your system for tracking business expenses aligns with the rules for an IRS accountable plan. 

The IRS Accountable Plan Requirements

All reimbursements should meet these three requirements:

1. Business-Related: The business use of the mileage being reimbursed must be demonstrated to be both ordinary and necessary. Ordinary means it’s commonly accepted in your business or trade, and necessary means it’s helpful to your business or trade.  
2. Substantiation: Each employee must keep an up-to-date, IRS-compliant mileage log of each business trip. They must also provide this information to the employer in a reasonable time period to receive a reimbursement.
3. Returning Excess Amounts: When an employer pays an employee an amount that exceeds that which was incurred or spent, the employee must return it within a reasonable time period.

What Should Each Mileage Entry Include?

Each mileage log entry for each business trip should include:

• The date of each trip
• Its starting and ending addresses
• The business purpose of each trip
• The business mileage driven

The IRS highly values timeliness in mileage logs, and gives more weight to records made at or as close to the time of the actual trip as possible. Keeping logs as contemporaneous with travel as possible also helps maintain accuracy. 

As a general rule, tracking business expenses daily produces stronger records than trying to log a month of driving at once, rebuilding the details from memory. 

Submission Deadlines

What’s a “reasonable time period?” 

According the IRS’ fixed date safe harbor rules, a reasonable timeline includes:

• An advance paid within 30 days before the expense is incurred
• Substantiation within 60 days have the expense has been paid or incurred
• Excess amounts returned within 120 days after the expense is paid or incurred

Within your organization, set a recurring due date for mileage logs a few days ahead of each payroll run. Tracking business expenses on a pay-period schedule keeps every log within the 50-day substantiation limit. 

Catch Mileage Log Errors Before Payroll Runs

What’s in your employees’ mileage logs? Any fraudulent reporting, or calculation/data entry errors?

Are you sure?

Mistakes happen. It’s inevitable! But when errors in mileage logs get all the way to payroll without getting caught, that rounding error or duplicated entry or mistyped number might end up in the reimbursement. 

Paying them the wrong amount isn’t the best way to reimburse your hardworking employees, even if the original mistakes were theirs.

Letting unchecked mileage errors through your approval process also significantly weakens the recordkeeping behind each reimbursement. Inaccurate mileage reports – surprise! – are not IRS-compliant, which could render those payments nonaccountable, and therefore subject to taxes. 

You’ll also be in hot water with the IRS if your records aren’t complete or accurate enough to prove an audit trail. That’s not a great place to be.

Common Errors in Sales Mileage Logs 

Watch for these errors when tracking business expenses for members of your field team:

• Rounded or estimated distances
• Missing or vague business purpose
• Counting ineligible travel as business mileage
• Duplicate entries
• Logs rebuilt at the end of the month from memory

Review Logs Before Approval 

• Compare all distances logged with the mapped route between the two addresses. If the entry contains a higher number than the route, ask the employee to explain why.
• Check client trips against calendar appointments and CRM activity. Each trip logged should match a recorded meeting or visit.
• Compare each rep’s monthly total against prior months. Ask about any discrepancies not explained by the contents of the log itself.
• Return incomplete entries to the rep and have them submit the corrected log before payroll processing. 

Build Your Program for Tracking Business Expenses on Accurate Trip Records

Building a mileage reimbursement program for your field sales team depends on four things:

1. The reimbursement method
2. That the trips themselves qualify
3. What records workers submit
4. Ensuring those blogs are free of fraud or errors

You need all four in place so that whatever method you choose for tracking business expenses keeps reimbursements accurate and accountable. The accuracy of each mileage log depends on how mobile sales representatives track and record their business-related travel. 

Spreadsheets, paper logs, and other manual methods are rife with the opportunity for fraud and errors to make their way into expense reports and reimbursement payments – with the onus of catching those entries one at a time on managers and administrators. 

CompanyMileage gives companies an fast, easy, and automated platform for tracking business expenses, submitting and approving reports, and reimbursing work-related travel. 

SureMileage, our mileage reimbursement software, calculates mileage point-to-point, from each business address to the next, including each leg on a multi-stop day. 

Employees enter the addresses and SureMileage supplies the distance and total for reimbursement, keeping rounding errors and duplicate trips out of expense reports. 

All expense reports, once submitted, move through an automated expense approval workflow, easily customizable to meet the structure of your business. 

Because CompanyMileage’s systems integrate with all major and accounting software, your mobile employees are guaranteed a timely, accurate reimbursement payment, every time.

To learn more about how CompanyMileage can help your business and your team optimize mileage reimbursement and even save money in the process, contact us for a demo today!