The Short Answer

1. Business driving and commuting are not the same thing

One of the most common mistakes is treating every trip connected to work as deductible.

Ordinary commuting between your home and a regular workplace is generally personal and nondeductible.

It does not become business mileage because the commute is long. It does not become business mileage because you answer a business call while driving. And carrying business supplies in the car generally does not convert an otherwise personal commute into deductible transportation.

But driving between business locations is different.

Examples can include:

• client to client;
• client site to showroom;
• showroom to supplier;
• office to customer meeting;
• one business workplace to another.

There is also an important temporary-work-location rule.

If you have one or more regular work locations away from home, transportation between home and a temporary work location in the same trade or business can generally be deductible, even if the temporary location is within your normal metropolitan area.

A work location is generally temporary when the work there is realistically expected to last, and actually lasts, for one year or less, absent facts and circumstances indicating otherwise.

If you have no regular work location and no qualifying home office, the rule is narrower. Transportation from home to a temporary work location outside the metropolitan area where you live and normally work can generally be deductible, while home-to-temporary-work-location travel within that metropolitan area is generally commuting.

So the distinction is not simply:

Did I leave home to go to work?

The better questions are:

Do I have a regular work location? Is this location temporary? And where does my business day legally begin?

2. A qualifying home office can change where the business trip begins

This is where business mileage connects directly to the home-office rules.

If your home office qualifies as your principal place of business, transportation between that home office and another work location in the same trade or business can generally be deductible business transportation, whether the other location is regular or temporary.

For example, assume a self-employed designer performs administrative and management work from a qualifying home office and then drives to a client’s home for that same design business.

That trip can generally be business transportation rather than commuting.

But a qualifying home office is not the only way home-to-work-location travel can be deductible.

A taxpayer with a separate regular work location may also qualify under the temporary-work-location rule. And a taxpayer with no regular work location may still deduct transportation to a temporary site outside the metropolitan area where the taxpayer lives and normally works.

That distinction matters for businesses such as design, consulting, construction, repair work, and other professions where the taxpayer may regularly move among customer or project locations.

A home office therefore matters.

It just is not the entire commuting analysis.

3. Driving between business stops is usually the easier part

Once a business day has already started, the analysis is often more straightforward.

Suppose a designer drives:

Home office → Client → Tile showroom → Fabric vendor → Home office

If the home office qualifies as the principal place of business and all of those stops relate to the same business, the route can generally be business transportation.

Or suppose someone works from a separate office and drives:

Office → Client A → Client B → Office

Those trips between workplaces are generally business transportation as well.

The difficult part is usually not the middle of the day.

It is determining whether the first and last trip involving home are business transportation, deductible under a temporary-work-location rule, or ordinary commuting.

4. A personal stop does not turn the entire day into business mileage

Business and personal use have to be separated.

Suppose you leave a client meeting, stop at a supplier for the business, then make a personal grocery stop before going home.

The grocery portion does not become deductible merely because the day also involved business.

Similarly, if you take a personal detour while traveling between two business locations, the personal portion should not be treated as business mileage.

The practical rule is simple:

Track the business miles. Do not turn the personal part of the trip into business mileage.

This is another reason mileage records are more useful when they are created during the year rather than reconstructed at tax time.

5. The 2026 standard mileage rate changed in the middle of the year

For 2026, there are two business mileage rates.

January 1 through June 30, 2026: 72.5 cents per business mile

July 1 through December 31, 2026: 76 cents per business mile

IRS Announcement 2026-11 revised the rate to 76 cents for deductible business transportation expenses paid or incurred on or after July 1, 2026. The IRS stated that the midyear adjustment resulted from recent increases in fuel prices.

That means a taxpayer cannot simply multiply all 2026 business miles by one annual rate.

For example, assume:

• 1,000 business miles from January through June; and
• 1,000 business miles from July through December.

The deduction would be:

1,000 × $0.725 = $725

plus

1,000 × $0.76 = $760

for a total of:

$1,485

For Daisy’s October trip in the Episode:

46 business miles × $0.76 = $34.96

The number is real.

But it does not measure the value of the hours she spent driving.

That is a business-pricing question, not a mileage-deduction question.

6. The standard mileage rate is not just a gas deduction

A common misconception is that the mileage rate is simply a substitute for gasoline.

It is broader than that.

When you use the standard mileage rate, you generally do not separately deduct the business portion of items such as:

• gas and oil;
• maintenance and repairs;
• tires;
• insurance;
• vehicle registration;
• depreciation;
• lease payments.

Those costs are generally represented through the standard mileage method rather than deducted again separately.

Certain other costs can still be deductible separately.

Business-related parking fees and tolls generally can be deducted in addition to the standard mileage amount. A self-employed taxpayer may also be able to deduct the business portion of vehicle-loan interest and applicable state and local personal property taxes, to the extent otherwise allowable under the tax rules for interest and taxes.

Parking at your regular workplace as part of ordinary commuting is generally nondeductible.

So:

Mileage rate + gas receipts

is generally not the calculation.

But:

Mileage rate + certain separately allowable vehicle-related costs

can be.

7. The other method is actual vehicle expenses

Instead of the standard mileage rate, a taxpayer may be able to use the actual-expense method.

Actual vehicle expenses can include items such as:

• gas and oil;
• insurance;
• repairs and maintenance;
• tires;
• registration and licenses;
• lease payments;
• depreciation;
• parking and tolls.

If the vehicle is also used personally, only the business portion is generally deductible.

For example, if a taxpayer’s substantiated annual vehicle use is:

12,000 total miles

and

4,800 business miles

the business-use percentage is:

40%

The taxpayer would generally apply the applicable business-use percentage to expenses that must be allocated between business and personal use.

Actual expenses can sometimes produce a larger deduction.

They also require more records.

And depreciation can create consequences that continue beyond the current year.

8. Standard mileage vs. actual expenses is not always a free choice every year

The method decision can affect later years.

For an owned vehicle, if you want to use the standard mileage rate, you generally must choose it in the first year the vehicle is available for business use.

After that, you may generally switch from the standard mileage method to actual expenses in a later year.

But if you switch, depreciation is not completely reset. After using standard mileage, the vehicle generally must be depreciated using straight-line depreciation over its remaining estimated useful life, subject to the applicable Section 280F depreciation limitations.

Standard mileage also does not mean depreciation disappears for basis purposes.

Part of each year’s business standard mileage rate is treated as depreciation and reduces the vehicle’s basis. For 2026, that deemed depreciation amount is 35 cents per business mile.

For a leased vehicle, choosing the standard mileage rate generally means continuing to use that method for the entire lease period, including renewals.

Certain prior depreciation choices can also prevent later use of the standard mileage method, including depreciation using a method other than straight-line, a Section 179 deduction, special depreciation allowance, or MACRS.

For many small-business owners, this means the first-year decision is worth making deliberately.

The larger deduction this year is relevant.

Future flexibility and basis consequences matter too.

9. What should a mileage log actually contain?

Mileage is one of those deductions where trying to reconstruct an entire year from memory can become difficult very quickly.

Vehicle expenses are subject to strict substantiation rules. Adequate records generally need to establish the amount of the expense or mileage, the time and place of the use, and the business purpose.

A practical mileage log should generally capture:

• date;
• business destination;
• business purpose;
• mileage for each business use;
• total annual mileage;
• and other information needed to support the vehicle expense.

A mileage-tracking app can work.

A spreadsheet can work.

A written log can work.

The system matters less than whether the records are timely, consistent, and sufficient to show what actually happened.

Trying to replace missing vehicle records with a rough estimate after the fact is a poor position. Vehicle expenses are subject to the Section 274(d) substantiation rules, which do not permit the usual Cohan-style estimation approach.

10. Do you need every gas receipt if you use standard mileage?

Not for the purpose of separately deducting gasoline under the standard-mileage calculation, because gas is not deducted again on top of the mileage rate.

But that does not mean recordkeeping disappears.

You still need support for the business mileage itself.

And other separately deductible expenses, such as qualifying parking, tolls, interest, or personal property taxes, should still be documented when relevant.

If you use the actual-expense method, the documentation burden becomes broader because the underlying vehicle expenses themselves matter.

The simplest method is not the same as no records required.

11. California generally follows the federal car-expense rules

California generally follows the federal rules for business automobile expenses.

FTB Publication 984 recognizes the same two basic methods:

1. actual vehicle expenses; or

2. the applicable published federal standard mileage rate.

California also follows the federal approach to basic business transportation concepts such as travel from one workplace to another, business trips to customers or meetings, and travel to temporary workplaces, and it requires adequate records to substantiate the deduction.

For the basic question of business mileage versus personal driving and use of the federal standard mileage rate, the California treatment therefore generally follows the federal approach.

There can still be California differences when depreciation enters the calculation. California does not conform to every federal depreciation provision, including certain federal special or bonus depreciation rules.

So the transportation rule may be the same while the later depreciation calculation is not necessarily identical.

Records to Keep

For a vehicle used for both business and personal purposes, keep enough information to reconstruct the year without guessing.

A practical file may include:

• beginning and ending annual odometer readings;
• business mileage log;
• date and destination of each business trip;
• short business purpose;
• parking and toll receipts;
• total annual mileage;
• purchase or lease documents;
• actual vehicle expenses if using or evaluating the actual method;
• prior depreciation schedules if applicable;
• prior-year method used for the vehicle.

The important record is not the number you type into the tax software.

It is the record showing how you got there.

Common Mistakes

“I drove somewhere for work, so the mileage is deductible.”

Not automatically. Ordinary commuting is generally personal even when the trip is related to your job or business. The temporary-work-location and qualifying-home-office rules can change the result, but the business connection alone is not enough.

“My first client is automatically my first nondeductible commute of the day.”

Not necessarily. If you have no regular work location and no qualifying home office, travel from home to a temporary business location within your normal metropolitan area is generally commuting. But a qualifying principal-place-of-business home office can change that result. So can the temporary-work-location rules if you have another regular work location or the temporary site is outside the metropolitan area where you live and normally work.

“I can deduct mileage and gas.”

Generally not under the standard-mileage method. The rate already substitutes for many actual vehicle costs, although qualifying business parking and tolls, and in some cases separately allowable interest or personal property taxes, may still be deductible.

“I can decide between standard mileage and actual expenses whenever I want.”

Not always. First-year use of the vehicle, leasing, prior depreciation methods, Section 179, and special depreciation can restrict the available choices.

“I can rebuild the mileage log when I prepare the return.”

That is risky. Vehicle expenses are subject to strict substantiation rules, and unsupported estimates are not a substitute for adequate records.

“If I make one personal stop, none of the day is deductible.”

Not necessarily. Business and personal mileage should be separated. A personal stop does not automatically erase otherwise qualifying business transportation.

The Key Distinction

1. Business activity does not automatically make the drive business mileage. The route, work locations, temporary-work-location rules, and purpose still matter.

2. A qualifying home office can change the first and last trip of the day. But it is not the only exception to the ordinary commuting rule.

3. The mileage deduction measures vehicle cost, not the value of your time. A profitable-looking project can still require more driving and coordination than the fee reflects.

The deduction belongs on the tax return.

The time belongs in the business decision.

Reference

Business Transportation and Vehicle Expenses

IRS Publication 463 — Travel, Gift, and Car Expenses

Primary IRS guidance on local business transportation, commuting, vehicle deductions, standard mileage, actual expenses, and substantiation.

Rev. Rul. 99-7 — Daily Transportation Expenses

Core authority distinguishing ordinary commuting from deductible transportation to temporary work locations and transportation from a qualifying principal-place-of-business home office.

Rev. Proc. 2019-46 — Standard Mileage Rate and Related Rules

Rules for using the business standard mileage rate, separately deductible parking, tolls, interest and taxes, method restrictions, depreciation treatment, and leased vehicles.

IRS — Standard Mileage Rates

IRS table showing the 2026 split-year business rates: 72.5 cents per mile for January through June and 76 cents per mile for July through December.

IRS Announcement 2026-11 — Midyear Mileage Rate Increase

Official authority increasing the business standard mileage rate to 76 cents for deductible transportation expenses paid or incurred on or after July 1, 2026.

IRS Notice 2026-10 — 2026 Standard Mileage Rates

Original 2026 mileage-rate notice and the source for the 35-cent-per-mile depreciation component used to reduce vehicle basis for 2026 business miles.

Home Office Connection

IRS Publication 587 — Business Use of Your Home

Explains when a home office can qualify as a principal place of business and the broader federal home-office rules.

California

California FTB Publication 984 — Business Expenses

California guidance stating that automobile expenses generally follow federal rules, including actual-expense and standard-mileage methods, temporary-workplace travel, and substantiation.

See This Rule in the Story

Between Stops

Daisy thinks of her current design project as small until one day takes her from a client meeting to multiple showrooms and a vendor.

The mileage creates a potential deduction.

But tracking the drive reveals something more important first: a project can require much more time than the client-facing work alone suggests.

That becomes a pricing question before it becomes a tax question.

Related Tax Guide

Home Office Deduction: When Does Your Workspace Actually Qualify?

A qualifying home office does more than potentially create a home-office deduction.

When it is the taxpayer’s principal place of business, it can also affect whether the drive from home to another business location is deductible transportation or nondeductible commuting.