Occasionally, your carrier might request the payment of additional fees due to the customs clearance process performed at the parcel's destination country.
For orders placed on Arduino's EU store, customs fees might occur for parcels shipped to countries outside the European Union. Similarly, the same might happen for orders placed on Arduino's US store and delivered to an area outside the USA.
The customs fees are regulated by the local authorities in the destination country. That fact makes it impossible to predict if you will be charged customs fees when ordering a product from the Arduino store.
Beware that the ordered parcel will be returned to Arduino's warehouse if this fee is not paid to the carrier.
Note: Even though it is impossible to predict if additional fees will occur, in some cases, although being slower, deliveries made by postal services are less likely to be charged customs fees.