Can ShipStation compare carrier rates automatically?

Yes — ShipStation's Rate Shopper can automatically pick the lowest-cost service, but only for the package already assigned to a shipment. ShipStation's own documentation (help article 4415714484123) notes Rate Shopper "only compares services. It does not compare different package types." ShipExtension decides the package first — which box (or boxes) a multi-item order physically fits — then rate-shops every service across all your connected carrier accounts and applies the lowest-cost eligible one in bulk, with a per-order audit trail.

Does ShipExtension rate-shop across multiple carrier accounts?

Yes. It compares live rates across all of your connected accounts — USPS, UPS, FedEx, and more — and can rate-shop per service, so each order gets the best-priced option you allow.

How is this different from ShipStation's built-in rate calculator?

ShipStation's Rate Shopper can now pick the lowest-cost service automatically, but it only compares services for the package already on the shipment — it doesn't decide which box a multi-item order needs, and native SKU rules skip multi-item orders entirely. ShipExtension decides the package first, rate-shops every service across all your carrier accounts as part of your automation rules, and re-runs whole batches after import — so the lowest-cost eligible service is selected without anyone comparing rates by hand.

Will rate shopping use my own negotiated rates?

Yes. Rate shopping runs on the carrier accounts you connect, so it uses your negotiated rates and keeps every carrier relationship intact. ShipExtension picks between the rates you already have.

Can I control which carriers and services it chooses?

You can. You decide which carriers and services are eligible and set per-service filters, so rate shopping only ever selects options you've approved for that order.

Rate Shopping

Rate shopping that starts with the right box.

ShipStation's Rate Shopper picks the lowest-cost service for the package already on the shipment. ShipExtension decides the package first — then compares every service across every carrier account you own and applies the lowest-cost eligible one, in bulk. It runs as one step inside your automation rules, and pairs with box optimization so you're shopping rates for the smallest box that actually fits.

Decide the right box first, then compare every carrier account automatically
Apply the lowest-cost eligible service to orders in bulk
Works with FedEx, UPS, USPS, and all ShipStation carriers

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Order #4521 • 5 lbs • Zone 4

USPS Priority

2-3 days

$8.45

FedEx Ground

3-5 days

$9.82

UPS Ground

3-5 days

$11.23

Saving $2.78 on this order

Smart Express Optimization

Stop overpaying for air when ground arrives on time

When customers pay for 2-day shipping, you don't always need to use 2-Day Air. If FedEx Ground will arrive in 1 day anyway, why pay the premium?

Example: NY → NJ Shipment

📦

Customer pays for 2-day delivery

Standard approach: Use FedEx 2Day ($18.50)

🧠

ShipExtension checks transit times

FedEx Ground arrives in 1 day for this route

💰

Uses Ground instead — saves $10.50

Customer still gets it on time. You keep the margin.

$10-20

saved per express shipment

when ground meets the delivery promise

How It Works

Set it once, save on every shipment

Configure your carriers

Select which carriers and services to include in rate shopping. Set rules for express orders.

We compare rates

For each order, we fetch live rates from all carriers, check transit times, and find the best option.

Apply in bulk

Run rate shopping on all pending orders with one click. ShipStation is updated automatically.

Doing it in ShipStation vs ShipExtension

Getting the lowest-cost eligible service on every order

ShipStation

Rate Shopper picks the lowest-cost service for the package already assigned to the shipment — it doesn't compare package types or decide which box a multi-item order needs

ShipExtension

Decide the box first, then rate-shop every service across all your carrier accounts and apply the lowest-cost eligible one in bulk — with a per-order audit trail

Always-on rate optimization

ShipStation's own documentation notes Rate Shopper "only compares services. It does not compare different package types" (help article 4415714484123), and that automation rules matching Item SKU "will only apply to orders containing a single unique line item" (help article 1260807687290), as of July 2026.

FAQ

ShipStation rate shopping FAQ

Can ShipStation compare carrier rates automatically?: Yes — ShipStation's Rate Shopper can automatically pick the lowest-cost service, but only for the package already assigned to a shipment. ShipStation's own documentation (help article 4415714484123) notes Rate Shopper "only compares services. It does not compare different package types." ShipExtension decides the package first — which box (or boxes) a multi-item order physically fits — then rate-shops every service across all your connected carrier accounts and applies the lowest-cost eligible one in bulk, with a per-order audit trail.
Does ShipExtension rate-shop across multiple carrier accounts?: Yes. It compares live rates across all of your connected accounts — USPS, UPS, FedEx, and more — and can rate-shop per service, so each order gets the best-priced option you allow.
How is this different from ShipStation's built-in rate calculator?: ShipStation's Rate Shopper can now pick the lowest-cost service automatically, but it only compares services for the package already on the shipment — it doesn't decide which box a multi-item order needs, and native SKU rules skip multi-item orders entirely. ShipExtension decides the package first, rate-shops every service across all your carrier accounts as part of your automation rules, and re-runs whole batches after import — so the lowest-cost eligible service is selected without anyone comparing rates by hand.
Will rate shopping use my own negotiated rates?: Yes. Rate shopping runs on the carrier accounts you connect, so it uses your negotiated rates and keeps every carrier relationship intact. ShipExtension picks between the rates you already have.
Can I control which carriers and services it chooses?: You can. You decide which carriers and services are eligible and set per-service filters, so rate shopping only ever selects options you've approved for that order.

Last reviewed July 17, 2026. ShipStation capabilities and pricing cited from ShipStation's help center and pricing page as of July 2026.

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