Why You Can’t Claim Petrol (If You Use Your Car Personally) – And What You Should Be Doing Instead
For many self-employed people—especially dog walkers, pet sitters, cleaners, and mobile trades—your vehicle is essential to your business.
But one of the most common mistakes we see at Cashtrak is this:
Claiming petrol receipts as a business expense when the car is also used personally.
Let’s break down why that’s not correct, what HMRC expects, and how you can claim the right way (without over complicating things).
Why you can’t just claim petrol
If your vehicle is used for both business and personal use, HMRC does not allow you to simply claim:
Fuel
Repairs
Insurance
Road tax
as full business expenses.
Why?
Because those costs relate to both:
Personal journeys
Business journeys
So unless you are:
👉 Apportioning all costs accurately (which is complex)
👉 OR using the alternative method (recommended below)
You cannot just claim petrol receipts as business expenses.
The correct method: Mileage
For most self-employed people, HMRC expects you to use the simplified mileage method.
Current rates:
55p per mile (first 10,000 miles)
25p per mile (after that)
This rate already includes:
Fuel
Repairs
Insurance
Wear and tear
So you don’t claim petrol separately
It’s simpler and often more beneficial
Why you MUST keep a mileage log
To use mileage correctly, you need a record of:
Date of journey
Start and end location
Number of miles
Business purpose
Without this, your claim:
May not be allowed by HMRC
Cannot be evidenced in a tax INSPECTION
Spreadsheet vs Mileage App
You can track mileage in a spreadsheet… but let’s be honest:
Spreadsheet
Easy to forget journeys
Time-consuming
Prone to guesswork
No audit trail
Mileage App (we use Tripcatcher)
This is where tools like Tripcatcher come in.
Tripcatcher:
Automatically tracks journeys via GPS
Lets you swipe trips as business or personal
Produces clean reports for your accountant
Keeps everything stored securely
And crucially:
It costs less than a cup of coffee a month.
Why this is ideal for dog walkers & sitters
For anyone:
Visiting multiple clients per day
Driving between locations constantly
👉 Manual tracking is unrealistic
Tripcatcher:
Runs in the background
Captures every trip
Ensures you don’t miss claimable mileage
Which often means: Higher (and accurate) expense claims
Less admin stress
But what about petrol receipts?
This is where people get confused…
Even though you don’t claim petrol when using mileage:
👉 We still need your petrol receipts
Why?
At Cashtrak, we use them to:
Make sure all business spending is recorded
Support VAT claims (if registered)
Cross-check for completeness
Evidence overall vehicle use if ever required
So:
Not claimed as an expense (under mileage method)
Still important records for your accounts
How Cashtrak can help
We don’t just “do the accounts”—we help you get it right from day one.
With clients like dog walkers and mobile businesses, we:
Set you up with the correct mileage method
Recommend simple, cost efficient tools like Tripcatcher
Make sure you’re not over- or under-claiming
Keep your records HMRC-compliant
Take the stress out of bookkeeping
Final takeaway
If you remember one thing, make it this:
If your car is used for personal and business use, you should be claiming mileage—not petrol.
And the easiest way to stay compliant?
👉 Track everything properly
👉 Use tools that save you time
👉 Get support from accountants who understand your business
Need help setting this up?
If you’re self-employed and not sure:
What you can claim
How to track mileage
Or how to stay compliant
Cashtrak can help you put a simple, stress-free system in place.