Fenix provides out of the box support for many carriers (100+) across the US and the world. The retailers will not be charged any fee to enable/disable the carriers. Some of the carriers supported by Fenix are listed below.
United States
FedEx
UPS
USPS
DHL eCommerce
Newgistics
Ontrac
DHL Express
Stamps.com
Lasership
Access Worldwide
FirstMile
Asendia
XDelivery
LSO
Better Trucks
Swyft
Uber
Australia
Australia Post
Sendle
UPS
FedEx
DHL Australia
Aramax
Couriers Please
My Post Business
Star Track
Seko
Canada
FedEx
UPS
DHL eCommerce
Canada Post
DHL Express
Purolator
Canpar
Seko
United Kingdom
FedEx
UPS
Royal Mail
DPD
DHL Express
Parcel Force
...