If you get registered with the post office you can get a number called an MID or mailer ID.
It's something that you should be able to have in encoded in the tick marks on first class letters and flats. It allows people to see where they are in the post office system without having first class tracking.
For those who ship a lot of letters and flats, allowing us to use our own MID's instead of stamps.com's would allow us to provide better service to our customers.
So, we recently got those MID's and CRID's for our two additional locations we plan to ship from. I was wondering if these ID's need to be added somewhere in Shipstation in order to get the USPS discounts? I have been told by our USPS rep they are tied to our discounts. Thanks!