As an ecommerce retailer, you're always looking for ways to cut shipping costs and protect your margins. Carrier adjustments are one of the biggest reasons those costs creep up. A carrier adjustment is an extra charge the carrier applies after a shipment is already in transit, added on top of what you paid for the label.
| Note: Carrier adjustments come directly from the carrier and are outside of our control. Carriers use highly calibrated technology to weigh, measure, and audit shipments as they move through their network, and these systems catch overweight packages, irregular sizes, and boxes that bulge in transit with a lot of accuracy. That's why it matters so much to enter accurate shipment information in Shippo before you buy a label. |
Common carrier adjustments and how to avoid them
Fuel carrier adjustment
Carriers charge a fuel carrier adjustment to account for changes in fuel prices. It's typically calculated as a percentage of your base rate, and the percentage varies by carrier and service.
You can review a carrier's fuel adjustment rate before you ship. If your delivery timeline has some flexibility, choosing ground over air can lower your shipping costs and reduce fuel-related adjustments.
Customs duty carrier adjustment
A customs duty carrier adjustment (also called a customs duty fee or tariff) is a charge a country's government applies to imported goods. Duties depend on the value or quantity of the goods and vary widely by product, origin, destination, and trade policy. Because these are government-set fees, there's no way to avoid or reduce this one when it applies.
Learn more: Understanding Customs Declarations
Residential carrier adjustment
A residential carrier adjustment is an extra charge for delivering to a residential address instead of a commercial one. Carriers classify some residences as standalone homes and others as businesses run out of a home, and this adjustment reflects the added cost and complexity of delivering to a residence.
FedEx and UPS apply residential adjustments on some services. USPS doesn't charge for residential delivery.
Peak carrier adjustment
A peak carrier adjustment is an extra fee added on top of a carrier's base rate during high-demand periods. Early October through mid-January is the most common peak window, since carriers see higher costs during the holiday shipping rush.
Depending on your package and destination, switching carriers or service levels during peak season can save you real money.
Shipment adjustments (billing corrections)
A shipment adjustment applies when there's a mismatch in your shipment data, like a difference in dimensions, weight, or address quality, that leads to a billing correction.
Here's how to avoid one:
- Weight: Enter accurate weights when you buy a label. Carrier audits are precise, so round up to account for home scale inaccuracies. If your package weighs 7.2 lbs., enter 7.5 lbs., not 7 lbs.
- Dimensions: Enter accurate dimensions when you buy a label. Dimensional weight may apply, and correct dimensions help you avoid underpaying on postage. Round up to account for shifting during transit. If your package measures 5.7 in. x 5.7 in. x 5.7 in., enter 6 in. x 6 in. x 6 in. Most carriers round up to the nearest inch anyway.
- Correct address: Enter the right address and ZIP code for both origin and destination. Discrepancies can trigger extra charges, so double-check the address on your label after you buy it.
How we pass along carrier adjustments
You'll find any carrier adjustments applied to your account in your invoices and transactions, under the Billing tab. Most carrier adjustments show up 30-60 days after you ship the parcel, though timing varies by adjustment type and shipment details.
Each carrier applies its own set of adjustments based on its service levels. Here's what to know, carrier by carrier.
USPS carrier adjustments
If USPS finds an issue with a package, it charges you the difference between what you paid and what the label should have cost.
Tip: Use the correct dimensions and weight for your service to avoid rate adjustments. For more detail, see USPS's guide to verifying postage.
Fees and adjustments can apply to Priority Mail, Priority Mail Express, First Class International, and Ground Advantage shipments based on package volume and dimensions.
Dimensional and nonstandard carrier adjustment details
If your dimensions are missing or inaccurate, USPS adds a $1.50 fee to packages over 1 cubic foot in volume or with a box length over 22 in.
If a package exceeds machinable sorting requirements, nonstandard sizing fees apply:
- Over 2 cubic feet in volume: $15.00
- Box length over 22 in.: $4.00
- Box length over 30 in.: $15.00
Learn more: USPS nonstandard fees and dimensional noncompliance fees
What is dimensional weight (DIM)?
Dimensional weight is a USPS pricing method for oversized packages that prices based on volume rather than actual weight. USPS applies DIM to domestic Priority Mail, Priority Mail Express, Non-Lightweight Parcel Select, and Ground Advantage packages over 1 cubic foot.
If USPS issues an adjustment tied to a weight discrepancy, it may be based on dimensional weight rather than the actual weight you entered at label creation.
Keep these in mind when shipping USPS:
- Nonstandard fee and dimensional noncompliance fee: Entering incorrect dimensions, or shipping a package with a side over 20 in. or 30 in. or a volume over 2 cubic feet, can trigger an adjustment.
- Dimensional weight divisor (effective July 12, 2025): The divisor drops from 166 to 139. The DIM formula is (length x width x height) / 139. Larger, lighter packages will calculate at a higher dimensional weight than before, so it's worth reviewing your dimensions if you ship bigger boxes.
Dimensional rounding changes (effective July 12, 2025)
For Priority Mail Express, Priority Mail, USPS Ground Advantage, and Parcel Select shipments, USPS rounds all dimensions up to the nearest whole inch. A package measuring 10.5 in. x 8.3 in. x 4.7 in. bills as 11 in. x 9 in. x 5 in.
Best practice: Measure accurately and enter correct dimensions to avoid surprise adjustments.
FedEx carrier adjustments
If you ship on Shippo's FedEx platform account, you're subject to additional carrier adjustments when they apply, and any extra charges show up on your Shippo invoice.
FedEx also has its own carrier-specific charges on top of the common ones above.
- Delivery area carrier adjustment: $13.25 per package for domestic shipments to select ZIP codes in the contiguous U.S. that FedEx designates as remote.
Learn more: FedEx's service guide and its 2023 surcharge changes.
Non-machinable carrier adjustment (FedEx)
Applies to any item that:
- Has one dimension over 27 in.
- Has any two dimensions each over 17 in.
- Weighs over 35 lbs.
- Ships in a cylindrical tube
Pick-up carrier adjustment
Applies when you request a FedEx pickup, whether through FedEx's electronic shipping tools or by calling to schedule one. Calling in a pickup request adds $4 per package.
Additional handling carrier adjustment
FedEx assesses this for packages that need special handling, including:
Dimension
- Longest side over 48 in.
- Second-longest side over 30 in.
- Length + girth over 105 in., where girth = (2 x height) + (2 x width)
Weight
- U.S. Express and Ground: over 50 lbs.
- International Express and Ground: over 70 lbs.
Packing (non-standard packaging)
- Not fully enclosed in a cardboard container, or enclosed in a non-cardboard container
- Wrapped in shrink or stretch wrap, bound with metal, plastic, or cloth banding, or fitted with wheels, casters, handles, or straps
- Packed in a soft-sided poly bag or bubble mailer exceeding 18 in. on the longest side, 13 in. on the second-longest side, or 5 in. in height
- Cylindrical or irregularly shaped in a way that could tangle in equipment or damage other packages
Fuel carrier adjustments (FedEx)
FedEx builds a fuel carrier adjustment into every rate, and it fluctuates with fuel prices. If an audit finds your shipment's dimensions or weight exceed what you entered at label creation, you may see additional fuel adjustments based on the audited numbers.
Learn more: FedEx U.S. fuel surcharges
DHL Express carrier adjustments
Fuel carrier adjustments (DHL Express)
DHL Express builds a variable fuel carrier adjustment into every rate, applied as a percentage of the shipping rate. The rates you see in Shippo already include it. For example, a $50 base rate with an 8% fuel adjustment adds $4, so you'd see $54 displayed.
Remote area carrier adjustments (non-disputable)
A remote area is a postcode, or a suburb or town if there's no postcode, that's difficult for DHL to serve. Delivering to a location on DHL's remote area list triggers this adjustment. Because DHL's remote area list can change daily, this adjustment is non-disputable and may not match the linked list at the time you check.
Emergency situation carrier adjustment (non-disputable)
Effective April 10, 2022, this is a temporary adjustment that covers operating cost increases from an emergency outside of DHL's control, like shifts in market dynamics or air capacity. DHL can adjust the fee as conditions change.
Learn more: DHL Emergency Situation Surcharge
Rounding note (DHL Express)
DHL doesn't accept partial dimensions and rounds every measurement up to the nearest whole inch. A package measuring 10.5 in. x 10.5 in. x 1.5 in. gets audited as 11 in. x 11 in. x 2 in. Round up each dimension when you create a label to avoid billing discrepancies.
Learn more: DHL surcharges
UPS carrier adjustments
If you ship on Shippo's UPS carrier account, you may be subject to additional carrier adjustments when they apply, reflected on your Shippo invoice. UPS applies carrier-specific charges at its discretion, including updates effective August 17, 2025.
Dimensional rounding changes (effective August 18, 2025)
UPS rounds all fractional billable dimensions up to the next whole inch. A length of 11.1 in. bills as 12 in. Measure accurately and enter correct dimensions to avoid surprise adjustments.
Domestic Large Package carrier adjustment (LPS) (effective August 17, 2025)
The previous rule was based on length plus girth. The new rule applies to domestic packages that meet either of these:
- Cubic size over 17,280 cubic in. (length x width x height)
- Actual weight over 110 lbs.
All other existing LPS criteria still apply.
Domestic Additional Handling Charge (AHC) (effective August 17, 2025)
The previous rule applied to packages exceeding length-plus-girth limits. The new rule applies to domestic packages with a cubic size over 8,640 cubic in. All other existing AHC criteria still apply.
Additional handling carrier adjustment (all services)
UPS assesses this for packages that need special handling, including:
Weight
- Domestic: over 50 lbs. actual weight (or average weight per package if individual weights aren't specified)
- International: over 70 lbs. actual weight (or average weight per package if individual weights aren't specified)
Length and width
- Longest side over 48 in.
- Second-longest side over 30 in.
Packaging
- Not fully encased in corrugated cardboard, or encased in a non-cardboard container like canvas, leather, metal, wood, plastic, or styrofoam
- Soft-sided packs (poly bags, bubble mailers) exceeding 18 in. on the longest side, 14 in. on the second-longest side, or 6 in. in height
- Wrapped in shrink or stretch wrap, bound with metal, plastic, or cloth banding, or fitted with wheels, casters, handles, or straps
- Cylindrical items like barrels, drums, or mailing tubes
- Routed through irregular sortation (for example, packages 1 in. or less in height)
- Anything else UPS determines needs special handling
| Note: If a package meets multiple criteria, only one Additional Handling charge applies, in this order: weight, length + girth, length, width, packaging. Additional Handling doesn't apply if the Large Package carrier adjustment already applies. |
Over Maximum (OverMax) carrier adjustment
Applies to packages over 150 lbs. actual weight, 108 in. in length, or 165 in. length plus girth combined. UPS may return packages over these limits at your expense, and the OverMax adjustment starts at $1,150 per package.
Learn more: UPS's guide to avoiding additional shipping fees
Evri carrier adjustments
Evri applies carrier adjustments based on delivery location, parcel weight, and delivery method.
Delivery location: Some remote UK locations carry a location charge due to distance from depots or ferry requirements.
Parcel weight: Overweight shipments (heavier than declared, or over the maximum) and larger international parcels can add cost depending on destination.
Delivery method: Your courier option affects overall price, and peak seasons like Black Friday and Christmas carry additional charges to maintain service levels.
Other adjustments: Relabeling, re-packaging, undeliverable parcels, and data correction.
International shipments through Evri include shipping and any fuel adjustment in the price. The recipient covers customs, duties, and taxes, which vary by country and contents.
Learn more: Evri: how to weigh your parcel
DPD carrier adjustments
DPD may apply carrier adjustments for:
- Oversized or overweight parcels (for example, UK parcels over 30 kg or 100 cm in length)
- Manual handling (for example, UK parcels over 175 cm in length or 300 cm in girth)
- Non-conveyable parcels (for example, Germany parcels over 120 cm in length or 60 cm in width/height)
- Address corrections
- Remote area deliveries
- Dangerous goods in limited quantities
- Returns to sender
Rates and conditions vary by country and can change over time. Learn more: DPD's surcharges list
Royal Mail carrier adjustments
Royal Mail may apply carrier adjustments for discrepancies in parcel weight, size, or postage. Most of these adjustments aren't disputable, though Royal Mail's reconciliation process may offer a path to review a dispute.
Discrepancies can come from:
- Shape changes in soft or non-rigid packaging during automated measurement
- Inaccurate weight or dimension declarations
- Packaging, barcode, or postage errors
Common reasons for Royal Mail carrier adjustments
| Reason | Typical fee | Notes |
| Declared weight or size doesn't match the actual parcel | £1.50 plus incremental postage | Measurement discrepancies are common with soft or expandable items |
| Oversized medium parcels (over 61 cm x 46 cm x 46 cm or 20 kg) | £10.00 | Measure accurately before you ship |
| No postage or counterfeit stamp usage | Variable | Verify your postage method before shipping |
| Outdated or non-barcoded stamps (not applicable via Shippo) | Variable | Avoid manual stamps on Shippo labels |
These shipments need extra accuracy in dimensions, weight, and barcode quality. If you want to dispute a charge, you'll need documentation like photos, scale readings, and manifest verification before you file.
Rates and conditions vary and can change over time. Learn more: Royal Mail's surcharges page
To learn how to avoid these adjustments in the first place, see Tips to Avoid Carrier Adjustments.