I sold 12 widgets to the same eBay buyer. Can i ship them all in one box, or do i need one tracking # per item?
The general rue of thumb is that you need at least as many tracking #s as payments. So if all 12 widgets were on one invoice, you need only one tracking #. If the buyer paid you in 12 separate payments, you need a tracking # for each and every payment. If this bothers you or the buyer, then refund and re-invoice into one payment, but be aware the buyer will probably want a shipping discount if you do this.