Shipping Carrier Selection Checklist

Export from ShipStation, the OMS, or carrier billing portals. You need package-level detail: zone, weight, billable weight, dimensions, residential flag, and accessorials. Aggregated monthly totals will not let you model effective rate against your real profile.

Bucket by weight band (under 1 lb, 1-5 lb, 5-20 lb, 20+) and flag where billable weight is driven by DIM rather than actual weight. Carriers price these segments very differently — a low-density apparel shipper has the opposite optimal carrier from a dense supplements shipper.

Residential surcharges (UPS, FedEx) and DAS (Delivery Area Surcharge) for extended/remote zips can swing 15-25% of net rate. DTC merchants are usually 90%+ residential — quote accordingly.

Send your ship profile (volume, zone distribution, weight bands) to each carrier's account exec. Also request quotes from regionals where you have density — OnTrac (West), LaserShip/OnTrac (East), GLS, Spee-Dee. Don't forget USPS via Pirate Ship or Stamps.com for lightweight parcels.

List rates mean nothing — apply each carrier's discounts to your actual package-level data and compute average cost per parcel. Tools like Shipware, Reveel, or a spreadsheet fed by 71-lbs/Sifted-style rate engines work. Compare net effective rate, not headline discounts.

Quantify residential, DAS, additional-handling, address-correction, fuel, and oversize surcharges as a percent of base rate. UPS/FedEx publish a General Rate Increase (GRI) every January — historically 5-7% — plus mid-year accessorial bumps. Negotiate caps on the worst exposures.

Pull each carrier's published transit map from your DC and overlay your top 25 demand ZIPs. A carrier that's a day faster to your largest customer regions is worth a price premium because conversion improves with shorter promised delivery.

Only USPS delivers to PO boxes and APO/FPO addresses. Regional carriers often skip rural zips, forcing a fallback to USPS or higher-DAS UPS/FedEx. Confirm the carrier's coverage matches your customer footprint before signing.

Determine whether this carrier needs to handle international parcels at all. Some merchants route international through DHL eCommerce, Asendia, Passport, or Easyship rather than the primary domestic carrier.

Confirm a native connector in your shipping software (ShipStation, Shippo, Easyship, ShipBob) or that the 3PL already handles the carrier. A carrier that requires custom integration adds engineering cost and ongoing maintenance.

Hit the rate API with sample parcels and confirm response time stays under 500ms — slower kills checkout conversion if you offer real-time rates. Generate test labels in sandbox and validate the format prints correctly on your 4x6 thermal printers.

Tracking events drive Klaviyo flows, Gorgias macros, and post-purchase pages. Confirm the carrier or aggregator (AfterShip, Shippo Track, EasyPost) delivers status updates within 2 hours of carrier scan and supports retries on webhook failure.

Push for tier discounts on your projected 12-month volume, capped GRI pass-through, residential surcharge waivers, and minimum-charge protection. Get a 30-60-90 day rate review clause so you can renegotiate if volume runs above forecast.

Add account credentials in ShipStation/Shippo/OMS, set up service-level routing rules (e.g., SurePost for sub-2-lb residential, Ground for everything else), and configure the storefront's checkout shipping options to match.

Ship 100-300 real orders through the new carrier across a representative zone mix. Reconcile the first invoice line-by-line against your modeled rate — surprises here (unbilled accessorials, billable-weight reclassifications) are why pilots exist.