The Bank of Slovenia always advises cash handlers to remain vigilant with regard to banknotes received in cash transactions. Genuine banknotes can be identified without difficulty using the FEEL-LOOK-TILT test.
Professional cash handlers are relatively vigilant about counterfeits, but otherwise individuals are insufficiently aware of the danger of being passed a counterfeit.
Some euro banknote counterfeits have high-quality imitation fluorescent features that can even fool professional cash handlers, and greater caution is thus recommended.
For more on the security features on euro banknotes, see the ECB website.