Every week, your carrier sends you a multi-page invoice. And every week, most Canadian small and medium-sized businesses pay it without reading it. It’s understandable: between service codes, two-decimal-place surcharges, and retroactive adjustments, a shipping invoice is designed to be approved, not audited.

The problem is that these invoices contain errors. Not always due to bad faith: a package mismeasured by a sorting machine, an address reclassified as a remote area, or an address correction charged even though the package was delivered on the first attempt. Industry estimates generally place the recoverable amounts between 2 % and 5 % from the annual transportation budget, and sometimes even more so among shippers who have never checked.

A shipping invoice audit It’s not rocket science. It’s a one-hour monthly routine that, for an SME spending 4,000 $ per month on transportation, often results in savings of 1,000 $ to 2,400 $ per year. Here’s how to set it up.

Why Shipping Invoices Contain So Many Errors

A shipping invoice isn’t a single price—it’s a breakdown of charges. There’s the base rate, then the fuel surcharge applied as a percentage, then the additional surcharges (residential, remote area, extra handling, address correction), and finally the taxes. Each component is calculated by a different system, sometimes several days after delivery.

Three mechanisms account for the majority of the discrepancies:

• Automated measurement. Sorting centers run your packages through tunnels that automatically measure and weigh them. A protruding strap or a slightly bulging box, and the volumetric weight charged goes up.
• Lists of ZIP codes. Carriers review the list of ZIP codes classified as remote or extended areas every year. A customer who wasn’t charged a surcharge last year may be charged one this year—or may be charged one by mistake.
• Retroactive adjustments. Many surcharges appear on a subsequent invoice, several weeks after the shipment was sent. As a result, they are rarely reconciled with the original shipment.

The Seven Most Common Billing Errors

Here’s what to look for, in order of return. The amounts below are estimates for 2026 and vary depending on the carrier, the negotiated agreement, and the service used.

The last two items are the most profitable and the most overlooked. A label that has been printed and then canceled is still billed by many carriers as long as no one requests a credit. And the money-back guarantee for late deliveries exists almost everywhere—but it’s never applied automatically.

How to Conduct the Audit, in Practical Terms

1. Bring your data back home

Ask your carrier for access to electronic invoicing. You’ll receive a detailed file—one line per package—that includes the tracking number, the billed weight, the recorded dimensions, and each surcharge listed in a separate column. This is far more useful than a summary PDF.

2. Create your internal reference

For your part, you’ll need the actual dimensions and weight of your standard boxes. Weigh and measure each of your box sizes thoroughly, write down the measurements, and you’ll have a permanent basis for comparison. Without this reference, it’s impossible to dispute a volumetric weight.

3. Sort by exception

Don't audit line by line. Sort your file by surcharge amount in descending order and focus on the 20 most expensive lines for the month. That's where most of the money is, and it only takes thirty minutes.

4. Check the tracking information before filing a dispute

For each issue, open a tracking request. A dispute supported by a delivery timestamp, proof of delivery to a business address, or a photo of your measured package is almost always successful. A dispute without proof will be denied.

5. File on time

This is the point where most claims fall through. The timeframes for disputing charges are short—often 15 to 90 days, depending on the carrier and the type of claim, and sometimes as little as 15 days for late-payment credits. An invoice reviewed six months later is no longer valid. Set a recurring monthly reminder for yourself.

What the Audit Reveals Beyond the Errors

The value of an audit extends beyond shipping costs. By consolidating 12 months of data, you’ll gain an accurate picture of your shipping profile: your average shipping zone, your average billed weight, the percentage of your shipments that trigger a residential surcharge, and the percentage of your packages shipped to remote areas.

These are exactly the figures a representative will ask you for during a renegotiation. Going into a rate negotiation by saying, «38 % of my shipments go to Zone 5 and beyond, and 71 % are residential,» completely shifts the balance of power compared to simply saying, «I’d like a better price.».

The audit also highlights operational issues: if address corrections are piling up, it’s your address validation process at the time of order that needs to be corrected, not the invoice. If shipping and handling fees recur every month for the same product, it’s the packaging that needs to be reviewed.

Should the audit be entrusted to a third party?

Specialized firms offer commission-based audits, typically charging between 25 % and 50 % of the amounts recovered. This is a model with no apparent risk, but it has two drawbacks: you give them access to your complete billing data, and a significant portion of the proceeds goes to them. For an SME that ships a few hundred packages per month, a monthly internal audit is almost always more cost-effective.

The decision to outsource is typically made when volumes are high—several thousand packages per month—at which point the number of lines makes manual verification impractical.

Put it into place this month

An audit of your shipping invoice takes just one hour a month and yields results that few internal initiatives can match. Start small: download your most recent itemized invoice, sort by surcharge, and look at the first twenty lines. In half an hour, you’ll know whether your carrier is billing you correctly.

At Shipping Store, we help small and medium-sized businesses and individuals across Canada compare carriers, understand their surcharges, and ship at the right price from the start—because the best billing error is the one you never have to dispute. Get a quote and compare your options at expertshipping.ca.

The amounts listed in this article are provided for informational purposes only for 2026 and vary depending on the carrier, the service selected, and the negotiated rate agreement. Always check the current claim schedules and deadlines with your carrier.