Shipping
Connect GLS US (formerly GSO)
West-coast regional parcel on your own GLS contract. US domestic, production only.
Overview
GLS US (formerly GSO) + TackQuote
GLS US — the carrier formerly known as GSO — is connected directly using your own shipper account, so rates and labels come from your contract and are billed to your GLS account with no aggregator per-label fee on top. Two limits are stated here because they are safety facts rather than marketing caveats. First, this connection is US DOMESTIC ONLY: GLS does rate its international products, but buying those labels needs line items and customs data this connection does not carry, so an international lane is refused at the rate rather than at the counter, where you would already have quoted a buyer. Second, it is PRODUCTION ONLY: GLS publishes no sandbox, so every label bought through this connection is real and billable to your account. TackQuote refuses a connection set to "test" outright rather than quietly pointing it at the live host — a seller who selects test specifically to avoid spending money must never end up buying real postage instead. Authentication is its own scheme: a username and password travel as request headers and are exchanged for a short-lived token that every later call carries, which is neither OAuth nor HTTP Basic and is described as what it is.
Open a GLS US shipper account, have API credentials issued, then rate and ship domestically — knowing every label is live.
Before you start
What you'll need
- A GLS US shipper account with API credentials issued by GLS
- A GLS shipper account number of up to 10 digits — the account each label is billed to
- US domestic destinations only
- Production environment only — GLS publishes no sandbox, so every label is billable
Setup
How to connect GLS US (formerly GSO)
Get API credentials from GLS
Contact GLS US to open a shipper account and have API credentials issued. The API itself is documented publicly at shipmenthub.gls-us.com, so nothing here rests on a guessed contract.Store the username, password and account number
All three belong under Settings → Shipping Carriers, and the connection must be set to production because no other environment exists.Rate, label, track
Request rates for a US domestic parcel, buy a label against a returned service, and pull tracking on demand. Treat every label purchase as spending real money, because it is.
Capabilities
What you get
Production Only — No Sandbox Exists
GLS publishes no test host, so every label is billable. A connection set to "test" is refused outright rather than silently pointed at production, which is the failure that would actually cost you money.
US Domestic Only, Refused Early
An international lane is refused at the rate request, before you quote it — not at the label counter after a buyer has accepted a price you cannot ship at.
No Per-Label Aggregator Fee
Rates and labels come from your own GLS US contract and are billed to your GLS account. Nothing adds a fee per label on top of the carrier charge.
Token Exchange, Named Accurately
A username and password sent as request headers are exchanged for a short-lived token, and the token is what every later call carries. Calling that OAuth or Basic would mislead you about which credential is in flight.
FAQ
GLS US (formerly GSO) questions
Is there a test environment for GLS US?
No. GLS publishes no sandbox, so every label bought through this connection is real and billed to your GLS account. TackQuote refuses a connection set to "test" rather than aliasing it to the live host, because a seller choosing test to avoid spending money must not spend it by accident.
Can I ship internationally with GLS through TackQuote?
No. GLS rates international products, but buying those labels needs line items and customs data this connection does not carry — so an international lane is refused at the rate request rather than after you have quoted a buyer.
Is GLS US the same as GSO?
Yes. GSO was rebranded GLS US, and the connection uses the credentials GLS issues for your shipper account rather than a gls-us.com portal login.
Can TackQuote void or refund a GLS label?
No. Void and refund are not implemented on any carrier connection. Since every GLS label is billable, reconcile any refund with GLS directly.