GST/HST on Late Fees, Chargebacks, and Pass-Through Costs

You send a client an invoice. The base service is straightforward. But then there is a late payment fee on top, or you are rebilling them for a software subscription you bought on their behalf, or processing a chargeback they owe you. Do you add GST/HST to those extra amounts?

This is genuinely confusing. The rules are not always obvious, and the wrong answer in either direction creates problems. This post walks through the general framework so you know what questions to bring to your accountant.

What Owners Get Wrong

The most common mistake is treating every line item on an invoice as either always taxable or never taxable based on what the primary service is. That is not how it works.

Some owners add GST/HST to everything they bill, including amounts where it does not apply, and end up remitting tax they never should have collected. Others skip it on items where it does apply and end up under-collecting, leaving themselves to cover the difference out of pocket when it comes time to file.

The general principle is that GST/HST applies to taxable supplies. If what you are charging for is a taxable supply (or closely connected to one), tax likely applies. If it is a true reimbursement of an exact cost with no markup, it may not. The line between the two is not always obvious.

The CFO Perspective: How to Think About Each Type

There are three common scenarios that create confusion: late fees, chargebacks to clients, and pass-through cost rebilling.

Late fees and interest charges: These are generally not subject to GST/HST because they are financial charges, not consideration for a supply of goods or services. If you charge a client an administrative late fee rather than an interest charge, the treatment can differ. The label matters less than the nature of the charge. Discuss the exact structure with your accountant, because the line between "administrative fee" and "interest charge" affects the tax treatment.

Chargebacks to clients: When a client owes you money because of a transaction that went sideways (a returned payment, a disputed charge that you lost and are passing back to them), whether GST/HST applies depends on whether the chargeback represents a recovery of a cost you incurred or a service you provided. True cost recovery with no margin is generally not a taxable supply. If you are marking it up or billing it as a service, that changes things.

Pass-through costs: This is where most owners get tripped up. You buy a software subscription for a client and re-bill it to them. Did you buy it as their agent? Or did you buy it yourself and resell it to them? If you acted as their agent (buying strictly on their behalf with their funds, with no markup), it may qualify as a disbursement and tax may not apply. If you bought it yourself and are selling it to them as part of your service, GST/HST almost certainly applies to the full amount including the software cost.

Here is a simplified example. A digital agency pays for a client's hosting plan ($100/month) and re-bills it at cost. If the agency is acting as a pure agent, the $100 rebill may be treated as a disbursement. But if the client never agreed to be billed for hosting separately and the agency just absorbs it and charges for it as part of a services invoice, it is part of the taxable supply. The documentation and intent matter as much as the dollar amount.

What to Do About It

1. Document how you handle pass-through costs before you start billing them. Is there a written agreement that you are acting as an agent? Is the client aware they are being billed the exact cost? This documentation is what supports your tax position.
2. Separate financial charges from service charges on invoices. If you charge both late fees and service fees on the same invoice, break them into separate line items. This makes the tax treatment of each clearer and easier to support.
3. Ask your accountant about the disbursement rules before assuming pass-throughs are tax-free. The criteria are specific. Not every cost you re-bill qualifies. Understanding the test in advance prevents over-collecting or under-collecting tax.
4. Be consistent across all clients. Whatever treatment you apply to one client for the same type of charge, apply to all. Inconsistent treatment across your book of business creates risk and makes year-end reconciliation harder.
5. If you are unsure about a specific line item, add the tax and note it clearly. It is much easier to refund a tax amount that was incorrectly charged than to go back to a client and collect tax you forgot to add six months ago.

Educational Note

This post describes how these rules generally work for educational purposes. The specific tax treatment of any charge depends on the facts of your situation, how your contracts are written, and CRA's guidance at the time you file. Talk to your accountant before changing how you bill or file. The rules around disbursements, agent relationships, and financial charges are nuanced enough that a five-minute conversation with a tax professional is worth it.

If you want to work through how your billing structure affects your GST/HST obligations, book a free call at peterxiacpa.com/book.

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