Business mileage deductions: what consultants need to know

Published February 18, 2026 · 2 min read

Business mileage deductions explained for consultants, with a worked example, a checklist and the mistakes to avoid.

Why this matters for consultants

Consultants usually bill large amounts irregularly, so setting aside the right share for tax is essential.

Worked example

Here is the calculation with sample figures. Change any number in the Mileage Deduction Calculator to run your own.

Business mileage deductions: how it works

Business miles can be deducted at a standard rate per mile instead of tracking every fuel and repair cost.

Commuting between home and a regular workplace usually does not count.

A second example with larger figures

Scaling the inputs up shows how the result moves. Percentages stay the same, so the tax grows in proportion to the amount it is applied to.

Using the calculator step by step

1. Open the Mileage Deduction Calculator.
2. Enter your own figures on each numbered line.
3. Set the rate to the one that applies to you. Defaults are examples, not advice.
4. Read the result and the formula below it.

Key terms

Net amount

The amount before tax is added. On an invoice it is the figure the tax is calculated on.

Exempt supply

A sale that falls outside the tax entirely. No tax is charged and input tax usually cannot be reclaimed.

Withholding

Tax deducted at source, by an employer or payer, before the money reaches you.

Reduced rate

A lower rate that applies to specific categories, often essentials such as food, medicine or books.

Deduction

An amount subtracted from taxable income. It saves tax equal to the deduction times your marginal rate.

A quick checklist for consultants

1. Keep a dated mileage log.
2. Separate business and personal trips.
3. Apply the current rate.

Common mistakes to avoid

• Claiming commuting miles.
• Estimating miles at year-end without a log.

Frequently asked questions

This article is general information for planning, not tax advice. Rates and rules change; confirm with your tax authority or a qualified adviser.