How to Reimburse Business Mileage Accurately

Why mileage claims are hard to get right

Mileage is one of the most common expense claims and one of the least consistent. An employee drives their own car to a client, a site or a supplier, then claims for the trip. Unlike a receipt, there is no printed total: the amount depends on the distance, the vehicle and the rate the company pays, and each of those can be entered differently by different people.

When employees calculate the amount themselves, the same trip is claimed at different rates, an old rate keeps being used after the policy changed, round trips are sometimes doubled and sometimes not, and approvers have no quick way to check the number. Finance then spends time recalculating claims instead of approving them.

The fix is to make the company rate the only source of the amount. The employee records the facts of the trip — the vehicle, the distance and where they went — and the system prices it. When the rate changes, it changes from a date, so trips before that date keep the old rate and trips after it get the new one.

Why this happens

• Employees type the claim amount themselves instead of a distance.
• A rate change is applied to trips that happened before it took effect.
• Round trips are doubled on some claims and not on others.
• Tax is added to mileage claims that should carry none.

Biznsbook addresses this through mileage rates per vehicle, mileage expense categories, distance-based claim lines, dated rate changes in the Expense Management module, which posts to the same general ledger as the rest of the ERP when Accounting is licensed.

Expense problems rarely come from one big mistake. They come from many small claims handled slightly differently each time. A single record per claim, with every decision and payment attached to it, removes that variation.

Step-by-step: Reimburse Business Mileage Accurately

Written for finance teams and office managers running staff spend — employees file claims, approvers sign them off, and finance pays and posts them, all inside the Biznsbook Expense Management module.

1. Add a rate for each vehicle type. In Expense Settings → Mileage rates, add a vehicle type such as Car or Motorcycle, choose kilometre or mile, enter the rate per unit in your base currency and the date it applies from.
2. Mark a mileage category. Open the expense category you use for travel by own vehicle and tick Mileage category. Lines in that category enter a vehicle and a distance instead of an amount.
3. Employees enter the trip. On a claim line in the mileage category, the employee picks the vehicle, types the distance, ticks Round trip to double it, and can note where the trip started and ended.
4. Let Biznsbook price the line. The amount is the distance times the vehicle's rate in force on the expense date, doubled for a round trip. The line carries no tax.
5. Approve it like any other claim. The mileage line sits on a normal claim, so it goes through the same approval stages, policy checks and reimbursement as every other line.
6. Change rates by date, not by editing. When the rate changes, add a new rate for the same vehicle with a later start date. Earlier claims keep the rate that applied to their trips.
7. Switch off rates you no longer use. A rate can be switched off instead of deleted, so claims that used it still show the rate they were paid at.

Review results after the first full monthly cycle. Adjust roles, mappings, or approvals where the same exception repeats.

Inside Biznsbook, the Expense module has its own step-by-step Guide (Expenses → Guide) covering claims, mileage, receipt scanning, approvals, advances, budgets and payments, and employees have Self Service → My Expenses. This article focuses on the business process behind those screens.

Common mistakes to avoid

• Mistake 1: Employees type the claim amount themselves instead of a distance. Repeating this each month usually shows up first in an expense report finance cannot reconcile to the ledger.
• Mistake 2: A rate change is applied to trips that happened before it took effect. Repeating this each month usually shows up first in an expense report finance cannot reconcile to the ledger.
• Mistake 3: Round trips are doubled on some claims and not on others. Repeating this each month usually shows up first in an expense report finance cannot reconcile to the ledger.
• Mistake 4: Tax is added to mileage claims that should carry none. Repeating this each month usually shows up first in an expense report finance cannot reconcile to the ledger.

Each of these shows up as a difference between the expense reports and the ledger. Fix the process on the claim record rather than with manual journals.

Best practices that hold up as you scale

• Add a rate for each vehicle type — In Expense Settings → Mileage rates, add a vehicle type such as Car or Motorcycle, choose kilometre or mile, enter the rate per unit in your base currency and the date it applies from.
• Mark a mileage category — Open the expense category you use for travel by own vehicle and tick Mileage category.
• Employees enter the trip — On a claim line in the mileage category, the employee picks the vehicle, types the distance, ticks Round trip to double it, and can note where the trip started and ended.
• Let Biznsbook price the line — The amount is the distance times the vehicle's rate in force on the expense date, doubled for a round trip.
• Approve it like any other claim — The mileage line sits on a normal claim, so it goes through the same approval stages, policy checks and reimbursement as every other line.

Keep the process inside the claim record. Every approval, payment and settlement recorded on the claim is one less manual journal to explain at month-end.

How Biznsbook supports this workflow

mileage rates per vehicle is part of Biznsbook Expense Management and follows the claim through the same record — submission, approval, payment and posting — rather than living in a separate spreadsheet. With Accounting licensed, each journal is posted as a balanced double entry under its own reference, so a payout or reversal can never be mistaken for the original expense.

mileage expense categories is part of Biznsbook Expense Management and follows the claim through the same record — submission, approval, payment and posting — rather than living in a separate spreadsheet. With Accounting licensed, each journal is posted as a balanced double entry under its own reference, so a payout or reversal can never be mistaken for the original expense.

distance-based claim lines is part of Biznsbook Expense Management and follows the claim through the same record — submission, approval, payment and posting — rather than living in a separate spreadsheet. With Accounting licensed, each journal is posted as a balanced double entry under its own reference, so a payout or reversal can never be mistaken for the original expense.

dated rate changes is part of Biznsbook Expense Management and follows the claim through the same record — submission, approval, payment and posting — rather than living in a separate spreadsheet. With Accounting licensed, each journal is posted as a balanced double entry under its own reference, so a payout or reversal can never be mistaken for the original expense.

Access is permission-based: Expense Manager holds approve, categories, budgets, settings and reports; Expense Approver can approve and view reports. Every company user can still file their own claims and advance requests, and company admins see everything.

Suggested implementation timeline

1. Week 1: Set up categories with GL accounts and the Expense Settings default accounts, then configure mileage rates per vehicle.
2. Week 2: Pilot with one team: file real claims, approve them and record payments in Biznsbook only.
3. Week 3: Check the postings: approved claims, employee payable and advances should match the expense reports.
4. Month 2: Roll out to all staff, assign Expense Manager and Expense Approver roles, and retire the spreadsheet.
5. Ongoing: Monthly review using reviewing mileage each month.

Related guides and help articles

Start with tracking business expenses efficiently and reimbursing employee expenses, then see expense approval workflows for who signs off each claim.

The Expense Management overview lists every capability, and Biznsbook vs Expensify compares an in-ERP expense module with a standalone app.

Industry: professional services, HR and people teams.

Metrics to track monthly

• Approved claims waiting for payment, and their total
• Average days from submission to final approval
• Outstanding employee advances past their expected settlement date
• Spend against budget by category for the month

Start with three metrics; trend direction matters more than a single point-in-time snapshot.

Spreadsheets and email vs Biznsbook Expense Management

Compare a typical email-and-spreadsheet expense process with Biznsbook mileage rates per vehicle and the related Expense capabilities.

Reviewing mileage each month

Look at mileage claims by employee for the month and compare distances with the trips you expect: client visits, site work or deliveries. Very long or very frequent trips are worth a question. When fuel prices or your policy change, add a new rate with the date it starts rather than editing the old one, so the history of what you paid stays intact.

Write the rule into your expense policy so employees, approvers and finance follow the same steps, and revisit it each quarter.

Frequently asked questions

How this differs by industry