I was informed the last time i was at TSB in Pt.Roberts that USPS requires anyone shipping there after September to fill out a document to verify their identity (USPS Form 1583). This form will generate an ID number and that ID must be on all shipping labels to TSB. If it is not there, or the form was never filled in, there is a possibility USPS will refuse to deliver the item and return it to Sender.
I asked TSB what this was all about they told me it was part of Fraud prevention, which makes me think all those items we ship to TSB that are USA Only may be part of this.
For ID they want to see your drivers license, passport, car insurance, home owners documents or a bunch of other items to clearly show your country of origin.
Sounds like shipping via USPS has just become more problematic. I wonder if Couriers will also follow this example soon.