The tax regulations on travel expenses have undergone constant changes in recent times. The new version of the income tax guidelines introduces fundamental changes to travel expense reimbursement. The long-standing differentiation between business trips, travel, and deployment activities will no longer be maintained in the future. The various types of external activities will now be grouped under a unified term. This system change significantly affects the conditions for tax-free reimbursement of travel expenses. The work explains the new travel expense law with the following focuses: redefinition of the regular workplace, changed conditions for the reimbursement of overnight, travel, and meal expenses, and tax-optimized structuring of mixed-purpose external activities.