Hey there @steve27,
You absolutely can connect your own direct USPS account! If you follow the steps found in this Knowledge Base article, you can certainly add your own Stamps account. While we offer that account to be utilized thru us, you are not required to use it.
I hope this helps! 🙂
This is the message I received from USPS
Your Stamps account/meter belongs to a reseller, the next step is that you reach out to Stamps and ask them to set up your account as a ‘stand-alone’ account.
Once that is set up, we will be able to upload the rates.