--- title: Declaring mileage and per diem description: "Declare a trip made with a personal vehicle, with the distance and amount calculated for you, then a per diem, the flat-rate meal and overnight allowance for a business trip." url: "http://illizeo.com/en/centre-aide/expenses-mileage-and-per-diem/" updated: "2026-11-01" category: Expense Reports --- # Declaring mileage and per diem This article is for employees who travel for work: it explains how to declare a trip made with a personal vehicle, with the distance and amount calculated for you, then how to declare a per diem, the flat-rate meal and overnight allowance for a business trip. ## Before you start - To declare a trip, your role must hold the "Submit a mileage expense report" permission at the **Execute** level; for a per diem, the "Per diem — Submit (country/dates, auto amount)" permission. The All employees, Manager, HR Manager, Payroll Manager and Administrator roles hold them by default. - The **Add mileage** button stays greyed out as long as your company has no active mileage category. - Only the mileage rates valid on the trip date, and open to your department and office, are offered. Only the countries with a configured per diem rate are offered. ## Declaring your vehicles A calculation based on a tax scale (fiscal horsepower, fuel) needs to know your vehicle. Declare it once: 1. In the **Expense Notes** tab of your profile, click **My vehicles**. 2. Click **+ Add a vehicle**. 3. Fill in the **Name** (mandatory), **Plate**, **Model**, **Fiscal horsepower** and **Fuel type** (Thermal, Diesel, Electric, Hybrid). 4. Click **Save**. If you have several vehicles, mark the one you use most as the **Default** vehicle. ![My vehicles window: no vehicle declared and the + Add a vehicle button](https://i0.wp.com/illizeo.com/wp-content/uploads/2026/11/expenses-mileage-and-per-diem-03.en_.png?resize=800%2C500&quality=80&ssl=1) The My vehicles window. ## Declaring a trip 1. Click **Add mileage**. The mileage category is chosen for you. 2. Give the trip a name and choose its **Date**. 3. Choose the **Rate**. A card summarises the selected rate: standard rate or tiered scale, vehicle group, annual cap and, where relevant, the country's legal settings. 4. Under **My vehicle**, check the vehicle used: a single vehicle is pre-selected; with several, choose it from the list. The **Manage** link opens your vehicles. 5. Enter the route: the starting point under **From**, then the destination. **Add another location** adds a stop. Addresses are completed automatically and your **Favorite places** (home, work…) are offered. 6. The **Distance (km)** is calculated from the route. Enter the **Occurrences** (number of times you made this trip, 365 at most) and tick **Round Trip** if needed. 7. The **Estimated Total** is calculated for you. Add a project, comments (500 characters at most) and a receipt if needed. 8. Click **Save Draft** or **Submit**. ![Mileage trip form: name, date and rate on the left, route map on the right](https://i0.wp.com/illizeo.com/wp-content/uploads/2026/11/expenses-mileage-and-per-diem-01.en_.png?resize=800%2C500&quality=80&ssl=1) The trip form: the rate is chosen after the date; the map shows the route. ### How the amount is calculated - The reimbursed distance is the route distance, doubled for a round trip and multiplied by the number of occurrences. If you correct the distance by hand, a "Distance changed" message reminds you that the route distance is the one reimbursed. - A tiered rate "per expense" applies its tiers to each trip; a tiered rate "per year" takes into account the kilometres you have already declared that year with this rate (pending or approved expenses dated before this trip). - If your company reimburses more than the country's tax exemption threshold, the difference is a taxable benefit. The trip's **Tax breakdown** then shows the tax-exempt part and the part subject to contributions, added to your payslip. ### Approval of a trip A trip of 200 km or less is approved automatically when submitted; beyond that, it follows your company's approval workflow. A trip whose exchange rate could not be determined always follows the workflow. ## Declaring a per diem 1. Click **Declare per diem**. 2. Fill in the **Trip Name**, **Start Date**, **End Date** and **Destination Country**. The **Applicable rates** box shows the country's amounts: meal, half day, full day and night. 3. Choose the **Trip Type**: **Half day**, **Full day** or **With overnight**. 4. If your employer provided meals, enter how many under **Meals provided by employer** (number of meals to deduct). Turn on **Accommodation provided** if you did not pay for your night. 5. Add a **Comment** if needed, check the **Estimated amount**, then click **Submit**. ![Declare a Per Diem window: trip name, dates, destination country, trip type, meals provided, accommodation provided and comment](https://i0.wp.com/illizeo.com/wp-content/uploads/2026/11/expenses-mileage-and-per-diem-02.en_.png?resize=800%2C500&quality=80&ssl=1) The Declare a Per Diem window. ### How the per diem is calculated - The number of days counts the first and last day; the number of nights is the number of days minus one. - Half day: days × half-day rate. Full day: days × full-day rate. With overnight: days × full-day rate, plus nights × night rate, unless accommodation was provided. - Each provided meal is deducted at the meal rate; the deduction cannot make the amount negative. - The rate used is the one in force on the trip's start date. Illizeo calculates the final amount when saving. ## Good to know - A per diem is submitted as soon as it is declared: it has no draft. While it is "Pending", you can delete it from the **Per Diem** tab; it can no longer be edited. - A per diem follows the same approval workflow as expense reports. - If no exchange rate exists for the date, a 1 to 1 rate is applied and flagged: check it after submitting. - If the map and address autocompletion are unavailable, a banner tells you; contact your administrator. ## FAQ ### The "Add mileage" button is greyed out Your company has no active mileage category. The administrator must reactivate it under **Settings › Expenses › Categories**. ### No rate is offered for my trip Choose the date first: only the rates valid on that date, and open to your department and office, are shown. If the list stays empty, contact your administrator. ### My destination country is not in the per diem list No active per diem rate is configured for that country. The administrator can add it under **Settings › Expenses › Per Diem**. ### *Similaire*