The UHF RFID frequency band is 860-960MHz. Different countries have different frequency bands among 860-960MHz.
Packages with tags are transferred to different countries with various RFID frequency band. However, the antenna has only one resonant frequency due to the fixed size. How this antenna adapt to all the frequency in different countries?
The antenna type matters: dipole structures are more wideband than patch antennas.
If you google for "bandwidth uhf rfid antenna" you will many approaches for antenna bandwidth enhancement. This works as long as the antenna has reasonable physical size.