Plain-English answers to the questions that come up before, during, and after you send a parcel abroad
Last reviewed on April 27, 2026.
CN22, CN23, and the commercial invoice — what each is for, when to use which, and how to fill them in without triggering a customs hold.
What you cannot ship internationally, what gets restricted by carrier or destination, and the categories where people most often get caught out.
Why a light, bulky parcel can cost more than a small heavy one — how DIM weight is calculated and the divisor each carrier uses.
How import duty, VAT, and handling fees stack up at the border, and how the de minimis threshold decides whether anything is owed at all.
When USPS Priority Mail International flat-rate boxes beat weight-based pricing — and when they don't.
What's included by default with each carrier, when buying additional coverage actually makes sense, and how claims tend to play out.
Realistic transit times by carrier and service, why customs is the real wildcard, and how to estimate when a package will actually arrive.
What drives the price — zones, billable weight, surcharges — plus reference cost tables and how to find the cheapest carrier.
Every carrier publishes its own prohibited and restricted list, and they don't match. Start with the universal list, then check the specific carrier you plan to use.
What no carrier will ship, plus country-specific bans.
Prohibited items & the nine dangerous-goods classes.
The nine hazard classes and how country acceptance works.
Global bans plus DHL's by-country restrictions.
Prohibited articles and contract-only restricted goods.
Non-mailable matter — stricter than the express carriers.
Country-level import bans in each country guide.
The recurring pain points are not exotic. Most stuck or returned parcels trace back to a small list of mistakes: