Harmonized Codes are a way for customs to determine what is in your package without having to decipher the language and/or handwriting. Learn more about how to use Harmonized Codes for international shipments.
Just keep in mind that for the USPS, Harmonized Codes are optional. If you are unsure about which code to use, the best option might be no code at all. Learn how to look up Harmonized Codes for your products.