All international packages will be processed at customs once it reaches the destination country. Customs mainly deals with importation and exportation, and will collect duties and taxes. Customs can often be the longest checkpoint for any package’s journey, so it’s not unusual to see it being processed for a few days or even a week.
If your package has been stuck at customs for over a week, please check your email and voicemail to see if you received a message from the carrier, as they will sometimes contact you regarding outstanding payments that need to be paid in order for your package to continue moving.
If you haven’t received an email or voicemail, please contact the carrier for more information, as well as your local customs office.