Duty refunds. Who can recheck the entries, and who can file.

An importer who thinks it has overpaid duty is asking two questions at once. Who may go through years of entries looking for the mistakes, and who may send the correction to CBSA. The rules answer the second question directly. The first one is open.

Who can file a duty refund in Canada

Since CARM release 3 went live on 21 October 2024, a refund of duty on commercial goods is an adjustment to the Commercial Accounting Declaration. Memorandum D17-2-1 names who may submit it:

"An adjustment may be submitted by an importer or an authorized representative, such as a customs broker or third party consultant, to which the importer has granted delegated authority to act on their behalf."

So the refund is filed in one of three ways: by the importer itself, by a customs broker, or by a third party consultant such as a duty recovery firm. The last two need the importer's delegated authority first, and the memorandum sends the reader to Memorandum D1-6-1, Authority to Act as Agent, for how that authority is given.

How the refund is filed in CARM

On that date the CAD replaced both the B3 coding form and the B2 adjustment form. An adjustment goes in through the CARM Client Portal, by EDI or by API. In the portal the importer or its representative selects the CAD and edits the fields that were wrong, and once CBSA accepts the change it becomes the next version of the same declaration.

Every adjustment carries a reason code that ties it to the section of the Act it relies on. A refund also has to be proven:

"Supporting documentation is required for all changes resulting in refunds during the adjustment period and must be uploaded via the CCP."

Two cases take a different path. An entry accounted for on a B3 before 21 October 2024 is adjusted under Memorandum D17-2-4, Preparation and Presentation of Pre-CARM Adjustments. And when the same error repeats across many CADs, one mass adjustment can cover two or more of them for the same legislative issue. The GST paid on an overpaid line does not come back with the duty; it is claimed from the CRA.

How far back a duty refund can go

Four years. Memorandum D6-2-3, Refund of Duties:

"Section 74 of the Act provides for a four year time period for the submission of refund claims with the exception of goods claimed under certain free trade agreements."

The window runs entry by entry, so each month the oldest month of entries falls out of it. Some refunds have a shorter clock of their own: remission of the 2025 surtax on US goods has to be claimed within two years of importation.

Who can recheck the entries before anything is filed

D17-2-1 decides who submits an adjustment. It says nothing about who may read the entries first, and that is where the work is: finding which lines, on which of hundreds of CADs, were declared wrong. The importer can do it, its broker can, a consultant can, and so can software. Whoever does it needs the same three things: the CADs as filed (or the B3s, for older entries), the commercial invoices behind them, and the Customs Tariff as it stood on the date of each entry.

A recheck can also find duty that was underpaid

Reading every line turns up underpayments as readily as overpayments, and the law does not treat the two the same way. D6-2-3 again:

"While corrections to declarations under section 32.2 are obligatory, refunds under section 74 of the Act are voluntary."

Claiming an overpayment is a choice. Once an importer has reason to believe a declaration is wrong, section 32.2 gives it 90 days to correct it. CBSA has four years of its own: under section 59 an officer may re-determine origin, tariff classification or value for duty within four years of the determination. A recheck worth having reports both directions, line by line, before anything is filed.