Separating Commuting from Business Mileage

This procedure documents facts behind driving categories; it is not a tax determination. IRS Publication 463, Chapter 4, “Commuting Expenses,” generally treats transportation between a residence and a main or regular workplace as commuting. It describes different treatment for certain temporary work locations, travel between workplaces, or travel from a qualifying home principal place of business. The rules depend on work locations and route. Employer reimbursement rules are not tax classifications.

Describe the trip before assigning a category

For each route, record date, origin, end point, work destinations, stop purposes, miles per segment, and whether each site is regular or temporary. Record the normal work location and assignment period; unfamiliarity alone does not make a site temporary. Publication 463 describes a temporary work location by reference to an assignment realistically expected to last, and that in fact lasts, one year or less, with additional rules based on regular work locations. Preserve facts needed to apply them.

Classify common routes cautiously

A routine drive from home to a regular workplace is generally commuting. Travel between workplaces and certain temporary job sites are addressed separately in Publication 463. A direct trip from home to a customer or temporary site needs closer analysis: treatment can depend on regular work locations, site location, and whether the residence qualifies as a principal place of business. Do not infer treatment from distance, a calendar label, or an employer request alone.

1. Write down origin, destination, stops, miles, and purpose for each segment.
2. Identify regular work locations and assignment duration from records.
3. Separate home-to-regular-work travel from travel between work sites.
4. Flag temporary-site, home-office, or multiple-workplace cases for review.
5. Apply the employer’s reimbursement policy only after the facts are recorded.

Worked example: home, office, then client location

An employee drives from home to the regular office, then to a client and back. Keep the home-office segment separate as a commute; log the office-client-office route with purpose and miles. If the employee drives directly from home to the client, do not copy that classification automatically. Record the route, regular work arrangement, and whether the client site is temporary, then refer it for review under Publication 463’s Transportation discussion.

Handle exceptions and mixed routes

If a route includes a personal stop, separate that segment when possible. For an employee with no regular work location, multiple jobs, a temporary assignment, or a claimed home principal place of business, collect facts and review the relevant IRS section rather than applying a universal rule. Hold unclear cases open. A manager’s request may support reimbursement but does not establish tax treatment.

Close the record transparently

Retain route details, assignment information, reviewer decision, and reimbursement outcome. Identify whether a decision applies company policy or IRS tax concepts; the two can differ. For unclear cases, consult current IRS guidance or qualified tax advice rather than extrapolating.

• Document route facts before labeling miles.
• Keep ordinary commuting separate from other work travel.
• Identify regular locations, assignment duration, and personal detours.
• Escalate home-office, temporary-site, and multiple-location cases.
• Record policy and tax conclusions as separate determinations.