Yes - When selecting a carrier and service within the READY TO SHIP page, ShippingEasy will automatically give you the best rate for the mail class selected, regardless of which carrier partner provides the rate.
Why do I need two Endicia accounts?
What rates does ShippingEasy offer on USPS shipments?
How do I know which Endicia account will be used for any given postage purchase?
Can I transfer money between Endicia accounts?
Why can't I buy or print labels on the READY TO SHIP page?