A 3PL can offer excellent warehouse pricing and still be expensive overall if outbound transportation is opaque. For many ecommerce brands, carrier charges are the largest variable cost in fulfillment, so understanding how a 3PL passes through parcel rates matters as much as pick-and-pack fees.
The key distinction is between the carrier discount the 3PL receives and the shipping rate the 3PL bills you. They are not necessarily the same number.
How 3PL shipping economics can work
| Model | How it works | What to verify |
|---|---|---|
| Pass-through carrier rate | Client is billed the 3PL’s negotiated carrier charge | Are all incentives and credits passed through? |
| Discounted published rate | Client receives a stated discount from carrier list/rack pricing | Discount from which rate table? |
| Rate + markup | 3PL adds a percentage or fixed margin | Markup basis and which charges it covers |
| Blended/zone rate | 3PL offers simplified custom rate card | How remote, fuel and handling fees are treated |
| Client carrier account | 3PL ships on client’s own account | Any processing or technology fee? |
A carrier discount does not automatically equal your savings
3PLs aggregate shipment volume and can negotiate parcel pricing unavailable to a small shipper. A provider-published 2026 guide from Red Stag Fulfillment cites carrier rates roughly 15–30% below retail as an example of 3PL purchasing power. That is not a universal market guarantee and does not tell you how much of the discount a specific provider passes to a client.
Ask to see actual sample shipment prices for your lanes rather than relying on a statement such as “up to X% off.”
Request a representative parcel basket
To compare providers, send the same sample shipments to every 3PL:
- origin warehouse ZIP/postal code
- destination ZIP/postal code
- packed dimensions
- actual weight
- residential/commercial flag
- service level
- declared value if relevant
Include normal orders and costly edge cases: remote ZIP codes, bulky lightweight cartons, heavier packages, Alaska/Hawaii if relevant, and high-zone residential shipments.
Compare fully loaded shipping cost
Use:
Fully loaded parcel cost = transportation rate + fuel + residential/DAS/remote + additional handling/oversize + declared value + demand/peak + 3PL shipping markup or fee
If one proposal only shows a base transportation rate, it is not ready for comparison.
Worked example
Suppose Provider A bills $8.40 transportation and passes through $1.10 of accessorials with no separate markup. Total: $9.50.
Provider B shows a lower $7.90 transportation rate but adds $1.10 accessorials and a 10% shipping markup on the $9.00 carrier charge:
$7.90 + $1.10 + $0.90 = $9.90
The provider with the lower headline base rate is more expensive after the commercial structure is applied. These figures are illustrative, not market benchmarks.
Questions to ask about parcel pricing
- Do we ship on your carrier account or ours?
- Are rates pass-through, marked up or based on a custom rate card?
- If there is a markup, what charges is it applied to?
- Are fuel and demand surcharges passed through at carrier cost?
- How are residential and delivery-area surcharges billed?
- Who receives carrier refunds and service-failure credits?
- Are address corrections and shipment adjustments passed through with a fee?
- Can we audit carrier invoices or receive charge-level detail?
- Do you use multiple carriers dynamically?
- Can we provide our own negotiated carrier account?
Why dimensional weight matters in this comparison
A 3PL may have a strong carrier discount but still create higher shipping cost if packaging is poorly right-sized. Compare the actual cartonization process and billing weight, not just the rate table.
Use the Dimensional Weight Calculator and Shipping Box Size Optimizer to test representative orders.
Model shipping separately from warehouse fulfillment
The 3PL Cost Calculator lets you include outbound shipping per order, but it is useful to compare warehouse-only fulfillment and transportation separately first. This exposes whether one provider wins because of operations, carrier pricing, or both.
Contract points worth documenting
- definition of pass-through rate
- markup formula
- frequency of carrier-rate updates
- treatment of annual general rate increases
- fuel and peak surcharge logic
- refund/credit ownership
- minimum parcel spend
- right to use client carrier account
- invoice-detail and audit rights
Frequently asked questions
Do 3PLs mark up shipping rates?
Some do, some use pass-through pricing, and others use negotiated custom rate cards. Ask for the exact commercial model in writing.
Can a 3PL get better carrier rates than a small ecommerce brand?
Often yes because aggregated volume can improve negotiating power, but the client benefit depends on the 3PL’s contract and pricing policy.
Should I choose the 3PL with the biggest advertised carrier discount?
No. Compare actual shipment examples and fully loaded charges. A discount percentage without the underlying rate basis can be misleading.
Can I use my own UPS/FedEx/DHL account with a 3PL?
Many providers support client-owned accounts, but policies and technology fees vary. Include this question in the RFP.
Sources
Shipping discounts and markups are contract-specific. Request real lane examples and current charge-level pricing.
PackToolbox guides are built around stated formulas, practical examples and source checks for changeable carrier, freight and logistics rules. Calculators are planning aids; final requirements should be verified with the relevant carrier or service provider.