How to Get Maximum Carrier Coverage Across Shipping Providers
Different shipping providers surface different carriers, which means connecting to only one provider can leave shipping options on the table. Shippo, EasyPost, and ShipEngine each have their own carrier integrations and agreements, so querying all three in parallel is the only reliable way to see every available rate for a given shipment.
Why does carrier coverage vary between shipping providers?
Each provider negotiates its own agreements with carriers independently. Some carriers are available across all three providers, while others show up only through specific integrations or account configurations. Regional carriers in particular tend to have spotty availability across providers.
Beyond which carriers are available, providers also differ in which services within a carrier they expose. You might get USPS Priority Mail through all three, but USPS Cubic rates might only appear through one.
Which carriers overlap between Shippo, EasyPost, and ShipEngine?
The major national carriers - USPS, UPS, and FedEx - are available through all three providers. That is the baseline. Where gaps appear is with regional and specialty carriers like OnTrac, LSO, and Spee-Dee, which are inconsistently available across providers.
- Regional carriers like OnTrac, LSO, and Spee-Dee are inconsistently available
- International options vary significantly between providers
- Carrier-specific negotiated rates depend on your provider account configuration
- Some carriers require separate account connections at the provider level
How do you maximize carrier coverage across providers?
Running rate requests through multiple providers in parallel is the only reliable way to see every available option. If Shippo returns 8 rates and EasyPost returns 11 for the same shipment, some of those 11 are carriers or services you would miss if you only queried Shippo.
The tradeoff is integration complexity. You need to call multiple APIs, normalize their different response formats, and deduplicate overlapping results before presenting options to the user.
How does RateShip handle multi-provider rate aggregation?
RateShip fans out to every provider the user has connected, runs all requests in parallel, and normalizes the results into a single sorted list. Rates from Shippo, EasyPost, and ShipEngine all come back in the same format, sorted by price.
If one provider fails or times out, you get results from the others with an error entry indicating what happened. You never miss rates because one provider had a hiccup.
What is the practical setup for maximum coverage?
For maximum coverage, connect all three providers. The overhead is minimal: paste in three API keys and RateShip handles the rest. You will consistently see more options, which means more opportunities to find the right carrier and service for each shipment.