In the European Union (EU), allergens used for diagnostic tests (TAs) are defined as medicinal products and have to be registered by national authorities. The current situation is not homogeneous. Existing authorizations need to be kept in the market in some EU states, while others need complete new authorizations requiring clinical trials, quality assurance methods, stability studies, and periodic safety update reports. Allergen manufacturers argue that offering a comprehensive panel of TAs may be economically disastrous. Expenses for initiation and maintenance of TA authorizations far exceed their related revenues and manufacturers may be forced to significantly limit their allergen portfolios. The availability of a wide range of high-quality TAs is very important for in vivo diagnoses of IgE-mediated allergies. Increased regulatory demands induce costs that need to be covered by public health organizations or reimbursed by health insurance companies.