Mileage log

What it means

A mileage log records trips in a company vehicle: date, route, purpose, kilometres and odometer reading. It evidences that the vehicle served the business rather than private use.

It supports claiming fuel costs at the consumption stated in the registration document. A company may instead choose the flat 80 % option, which replaces the log.

A trip log is kept for a vehicle the company owns or leases. When an employee or managing director makes a business trip in their own car, it is not company fuel but travel reimbursement: the firm pays them for the kilometres and fuel as the law sets out, and the basis is the travel order with a record of the journey.

How it works in practice

Under the flat rate no fuel above 80 % is claimed, but private use is allowed. With a log everything recorded and backed by fuel receipts can be claimed.

The log is kept as you drive. The modern answer is a GPS unit writing routes automatically, which on a larger fleet saves more time than any spreadsheet.

The log also matters for VAT. When the vehicle is used privately as well, the tax on fuel and repairs is deducted only to the extent of business use, and the log is the most accurate evidence of that share. For proportional deduction we therefore work the share out from the log, not by estimate.

What to watch out for

A log written up before a tax audit is exposed by comparing it to fuel purchases, service records and toll crossings. A contradiction means the cost is disallowed and tax assessed.

If an employee may use the company car privately, they receive a benefit in kind that is taxed and subject to contributions in payroll regardless of the log. The log does not replace it; a firm that leaves this benefit out of the payslip pays the tax and contributions retrospectively, with a penalty.