USPS First Class international tracks all the way to the destination address, at least for here in Thailand. Either by the registered number if the package is registered, or by the customs number if not registered. It's a pretty good service and rarely more than 12-14 days - except at the moment which can hardly be called normal. But the tracking is still working even so. For some odd reason, items leaving the US through Chicago are coming through almost as normal, but from Miami, San Francisco and New York are backed up.