SKULabs connects to shipping carriers through several supported providers. This guide covers all the ways to add a carrier, connect it to your stores, and manage your accounts over time.

When you add a shipping provider in SKULabs (Settings > Shipping > Carrier Accounts > Add carrier), you'll see a Type dropdown with every supported carrier and provider. SKULabs connects to carriers through four main paths:

You can connect multiple carrier accounts at the same time. SKULabs will show rates from all connected carriers on the ship window so you can compare and choose.

The Type dropdown is organized by region:

Carriers labeled (SKULabs) are direct SKULabs integrations. Carriers labeled (EasyPost), (Shippo), (Endicia), or (Stamps.com) route through those providers.

USPS, FedEx, UPS, and DHL Express can be connected directly in SKULabs. Select the carrier from the Type dropdown (e.g. USPS, FedEx, UPS, DHL Express) and follow the on-screen instructions to enter your account credentials.

The Misc section of the Type dropdown also lists FedEx (SKULabs), UPS (SKULabs), and DHL Express (SKULabs) — these are the same direct integrations, just organized differently in the list.

For carrier-specific step-by-step guides:

EasyPost is a shipping provider that gives you access to USPS, FedEx, UPS, DHL, Canada Post, Australia Post, and many other carriers through a single API. It's useful when you want to compare rates across multiple carriers, bring negotiated rates from your own carrier accounts, or access carriers not available as direct integrations.

If you don't already have one, sign up for a free EasyPost account. Use an email address on your private domain (e.g. you@yourcompany.com) — not a free email like Gmail or Yahoo. Using a free email domain can trigger EasyPost's anti-fraud flag and delay your account setup.

Once signed in, set up a payment method and auto-recharge plan on the Billing page. EasyPost charges no flat or monthly fees — you only pay for labels purchased.

EasyPost includes a default USPS connection automatically. For any other carrier (FedEx, UPS, DHL, Canada Post, etc.):

If you have multiple account numbers for the same carrier, add each one separately in EasyPost.

Shippo supports a range of carriers including DHL Express, LaserShip, OnTrac, and many regional European carriers. Carrier types labeled (Shippo) in the dropdown route through Shippo.

See also: How to add DHL Express through Shippo

After adding a carrier, you can control which stores have access to it. By default a newly added carrier is available to all stores. To customize:

Carrier credentials expire or change for several reasons: your carrier updated your account number, credentials were rotated, or you changed your carrier agreement. When this happens, you'll usually see errors like:

To reconnect:

If your carrier account no longer appears in the EasyPost dropdown, log into EasyPost, re-add the carrier account there, then return to SKULabs to complete the reconnection.

SKULabs supports connecting multiple carrier accounts simultaneously. Common setups include a direct FedEx account alongside USPS via EasyPost, multiple FedEx accounts for different stores, or a primary carrier plus a regional carrier as a backup.

When multiple carriers are connected, SKULabs shows rates from all of them on the ship window. Use Shipping rules (Settings > Shipping > Rules) to automatically assign a specific carrier to orders matching certain criteria, or use the Least expensive shipping method to have SKULabs automatically pick the cheapest rate across all connected carriers.

This prevents SKULabs from querying that carrier for rates without deleting it. Re-enable it by reassigning it to your stores when ready.

Switching carriers involves more than just adding the new one — several settings reference the old carrier and need to be updated. Full checklist:

See also: Switching primary carriers

Yes. When you connect your own carrier account — whether directly or through EasyPost — SKULabs uses your account's negotiated rates. Your carrier billing stays exactly the same.

Yes. EasyPost provides a default USPS connection with competitive rates as soon as you create an EasyPost account. No separate USPS account is needed to start shipping USPS through SKULabs. You can also connect USPS directly, or through Shippo, Stamps.com, or Endicia.

Yes. Once a carrier is added, you can assign it to any combination of your stores from the Carrier Accounts settings page.

Direct connections are straightforward if you only need that one carrier. EasyPost is useful when you want to compare rates across multiple carriers, access carriers without a direct SKULabs integration, or manage all your carrier accounts in one place with a single API key.

This depends on whether your carrier's rate data is compatible with EasyPost. See Can SKULabs install my rate card for a carrier I've connected by EasyPost?