If you come to work in the Netherlands, you are possibly confronted with extra costs, so-called extraterritorial costs.
Your employer may grant you a free (untaxed) reimbursement for the extraterritorial costs that you incur. Your employer may also provide you with 30% of your wage, including reimbursement, tax-free. This facility is known as the 30%-facility. For this, it is not necessary to prove that expenses have been incurred.