Allowances given by an employer to his employee to cover foreign business travel expenses are costs proper to the employer. These allowances are tax exempt for the employee (art. 31, al.1, 1° Belgian Income tax Code) and are deductible for the employer.

Daily lump-sum allowances paid to reimburse expenses incurred during short foreign business travel are exempt from tax to the extent they do not exceed the lump-sum per diem allowances paid by the Federal Public Service Foreign Affairs to its civil servants who go on a mission abroad, based on the official list published by Foreign Affairs (however, higher lump-sum can still be accepted if justified).

Daily lump-sum allowances are used to repay the sums that employees and company directors spend on meals and other minor expenses (local transportation, snacks and drinks, tips, local communications). They do not cover lodging or international travel costs.

These amounts apply for employees and company directors going on short business trips of up to 30 calendar days. The lump-sum allowances (i.e. if within the Federal Public Service of Foreign Affairs list limits) are considered as costs proper to the employer in the following cases:

- per full day spent abroad (i.e. with both the previous and the following night being spent on business trip). For departure and return days of a business travel of more than one day, the lump-sum allowance is regarded for up to 50% as costs proper to the employer.
- in the case of business travel involving an absence of the employee from his normal workplace of less than 24 hours, but 10 hours at least;

These lump-sum allowances paid to reimburse short business travel expenses are made up as follows:
- 15% of the allowance covers the costs of breakfast;
- 35% covers the costs of lunch;
- 45% covers the costs of evening meals;
- 5% meant to reimburse various other minor costs that are made during such business trips of short duration.

If the employee on a mission abroad only bears part of the costs, for instance, because evening meals are paid back separately on the basis of an expense note, the aforementioned percentages should be used and applied to the amounts indicated in the aforementioned list in order to avoid double reimbursement of expenses to the employee.