Carrier-calculated shipping

With carrier-calculated shipping, buyers see live rates from a real carrier at checkout instead of a price you set by hand. Sellerlane asks the carrier for a quote using the buyer’s address, the items in the cart and their weights, and shows the carrier’s services and prices — including any negotiated pricing on your carrier account, because the quotes come from your own account with that carrier.

You bring your own carrier account: sign up with the carrier directly, generate API credentials in their developer or business portal, and connect them under Settings → Shipping → Carrier accounts. Sellerlane never marks up or resells carrier rates.

Supported carriers

Carrier	Store countries served	Credentials you need
UPS	All supported store countries	Client ID, client secret, account number
FedEx	All supported store countries	Client ID, client secret, account number
USPS	United States	Client ID, client secret, pricing mode (commercial or retail)
DHL Express	All supported store countries	API key, API secret, account number
Canada Post	Canada	Username, password, customer number, and optionally a contract ID
Aramex	UAE, Saudi Arabia, Kuwait, Qatar, Bahrain, Oman	Username, password, account number, account PIN, account entity, account country
Shiprocket	India	Your Shiprocket account email and password
Australia Post	Australia	API key

“Store countries served” is matched against your store’s country — for example, a store based in India can connect UPS, FedEx, DHL Express, and Shiprocket, but not USPS. Carriers that don’t serve your store country don’t appear in the connect picker.

Note

Shiprocket is an aggregator that quotes across Blue Dart, Delhivery, and 15+ other Indian couriers from a single account, and is COD-aware — usually the fastest way for an Indian store to get carrier rates.

Connect a carrier account

1. Go to Settings → Shipping and open the Carrier accounts card.

2. Click Connect and pick the carrier. Only carriers that serve your store’s country are listed.

3. Enter the credential fields for that carrier (see the table above) and give the account a display name.

4. Save. Sellerlane immediately verifies the credentials with a live call to the carrier before activating the account. If verification fails, the account is saved but stays inactive, with the carrier’s error shown so you can fix the credentials and try again.

A few rules apply to accounts:

• One active account per carrier. You can connect many different carriers at once, but only one active account for each carrier per store.
• Credentials are re-checked periodically. Sellerlane sweeps carrier credentials in the background; if a carrier reports your credentials as invalid, the account is deactivated, you see a warning on the settings page, and any rates using it fall back to their backup rates.
• Test mode connects to the carrier’s sandbox environment instead of production — useful for trying out a new integration without live quotes. Switch it off before relying on the rates in a real checkout.
• Deleting an account is only possible when no shipping rate references it; otherwise deactivate it (its rates quote backups until you reconnect).

Add a carrier-calculated rate to a zone

Carrier rates live in the same place as your manual rates — inside a zone on a shipping profile.

1. Go to Settings → Shipping, open the profile with Manage Rates, and open (or create) the zone you want carrier rates in.

2. Click Add Shipping Rate and choose Carrier calculated as the rate type.

3. Pick the carrier account to quote from.

4. Tick the services you want to offer (for example UPS Ground and UPS 2nd Day Air but not Next Day Air). Buyers see one rate per service the carrier returns.

5. Optionally turn on Automatically include new services — when the carrier introduces a new service, it’s offered at checkout without you editing the rate.

6. Optionally add a handling fee (see below), then save.

You’ll be asked to add a backup rate before you can save a carrier rate into a zone that has no other visible rates — see Backup rates below.

Handling fees

Each carrier rate can add a handling fee on top of the carrier’s price, as a percentage, a flat amount, or both. The percentage is applied first, then the flat amount:

Carrier quotes $5.00 → add 50% → $7.50 → add $1.00 flat → buyer pays $8.50.

Negative values are allowed if you want to subsidize part of the carrier price — the final rate is never reduced below $0.00.

Backup rates

Carrier APIs occasionally go down, time out, or reject a request. A backup rate is a regular flat, price-based, or weight-based rate attached to a carrier rate that is normally hidden, and only shows when the carrier can’t be quoted — so checkout never blocks and the buyer never sees a carrier error.

• Backup rates are required when a carrier rate would otherwise be the only rate in its zone. Saving is rejected with a prompt to add a backup rate so checkout keeps working if the carrier is unavailable.
• Add backups from the carrier rate’s editor — each backup is a normal rate (name, cost, optional bounds) that stays hidden from checkout while the carrier is healthy.

Backup rates are shown when:

• the carrier request times out, errors, or is rate-limited, or the carrier has been failing repeatedly and quoting is temporarily paused;
• the carrier replied, but all of its rates were filtered out by Sellerlane — for example the response currency didn’t match your store currency, none of the returned services were on your allowlist, or the shipment origin isn’t served by that carrier.

Backup rates are not shown when the carrier successfully replies with no services for that address — that means the carrier genuinely can’t service the route, so nothing from that carrier is offered.

When a buyer completes checkout on a backup rate, the order records that the carrier was unavailable and which carrier failed, and the order page in your admin shows a banner — so you know the price charged came from your backup, not a live quote.

Troubleshooting

• Carrier rates don’t appear at checkout. Check that the carrier account is active (credentials verified) on Settings → Shipping → Carrier accounts, that the rate’s service list isn’t empty, and that the carrier’s response currency matches your store currency — rates in any other currency are dropped.
• One location quotes, another doesn’t. Carrier accounts only quote shipments whose origin location is in a country the carrier serves — for example, USPS only quotes shipments originating from a US location. Shipments from other origins fall back to that rate’s backup rates.
• A price or service change isn’t showing. Successful carrier quotes are cached for about 25 minutes per address and cart combination, so a change on the carrier’s side (or to your service selection) can take up to 25 minutes to appear for an address that was recently quoted. Failed quotes are retried after about 30 seconds.
• You want to know how often the carrier fails. The Carrier accounts card shows an event history — quote failures, times a backup rate was used, filtered rates, and credential problems — with 7-day and 30-day counts per account.

Caution

Your store currency must match the currency your carrier account quotes in. On a single-currency platform there is no conversion — mismatched quotes are silently dropped and backups shown instead. This is checked when you save the account where the carrier’s API allows a probe quote.

Next steps

Estimated delivery dates

Show delivery date ranges under your rates at checkout. Carrier rates use the carrier’s own dates automatically. See Estimated delivery dates.

Shipping & checkout

Profiles, zones, and manual rates — where your carrier rates live. See Shipping & checkout.