: The number is always printed on the bottom of the original retail box and listed on the official invoice. IQOS website How to Perform a Serial Number Check
For IQOS 2.4, 3, and 3 DUO:
Only use the official IQOS website for your specific region to verify codes. Registration: iqos serial number check
: Remove the cap; the code is printed on the side of the holder. : The number is always printed on the