Introduction

For a newly incorporated business in Ontario, the HST system is one of the first compliance obligations that needs to be understood and managed correctly. Get it right from the start and it becomes a manageable part of running the business. Get it wrong — by registering late, miscalculating ITCs, or missing remittance deadlines — and the consequences range from penalties and interest to a CRA audit.

This article explains how HST works for an incorporated business in Ontario.

The HST Rate in Ontario

Ontario applies a harmonised sales tax (HST) at a rate of 13%, which combines the 5% federal GST and the 8% Ontario provincial component. HST applies to most goods and services supplied in Ontario by a registered business.

There are three categories of supply for HST purposes:

Taxable supplies: Subject to HST at 13% (Ontario). The business charges HST, collects it, and remits it to the CRA, offsetting the HST it paid on its own inputs (input tax credits).

Zero-rated supplies: Technically taxable but at a rate of 0%. Examples include most basic groceries, prescription drugs, and exports of goods and services to non-residents. A business making zero-rated supplies is registered for HST, can claim ITCs, but charges no HST to clients.

Exempt supplies: Not subject to HST at all. Examples include most medical and dental services, educational services from regulated institutions, and residential rent. A business making exempt supplies does not charge HST and cannot claim ITCs on its inputs.

Most incorporated businesses in professional services, construction, technology, and retail make taxable supplies and are subject to the standard HST rules.

When Registration Is Required

A corporation must register for HST once its total taxable supplies in any four consecutive calendar quarters exceed $30,000. Once that threshold is crossed, the corporation must register promptly — there is no grace period after the threshold is reached.

Voluntary registration is also available for businesses below the $30,000 threshold. Voluntary registration makes sense when the business is paying significant HST on its inputs and wants to claim ITCs, even before reaching mandatory registration.

Failure to register when required exposes the corporation to back-assessment of HST owing on all supplies made since the threshold was crossed, plus penalties and interest.

Charging and Collecting HST

Once registered, the corporation must:

•  Include HST on invoices to clients for taxable supplies at the correct rate

•  Display the HST registration number on invoices

•  Separately identify the HST amount (or state that the price includes HST and calculate the included amount)

HST collected from clients is not corporate revenue — it is a liability owed to the CRA. Recording it separately in the accounting system from the outset prevents the common error of treating HST-inclusive receipts as income.

Input Tax Credits

The ITC mechanism is what makes HST a flow-through for most businesses: the corporation collects HST from clients and remits it to the CRA, but credits back the HST it paid on its own business inputs.

Eligible inputs include rent, professional services, supplies, equipment, software subscriptions, and other HST-bearing business expenses. The ITC is claimed on the HST return, reducing the net HST remittance.

To claim an ITC, the corporation must hold valid documentation: a supplier invoice or receipt that includes the supplier's GST/HST number, a description of the supply, the date, and the amount of HST charged.

Filing Frequency and Remittance Schedule

The CRA assigns a filing frequency to each registrant based on annual taxable revenues:

•  Monthly: Annual taxable revenues exceeding $6 million

•  Quarterly: Annual taxable revenues between $1.5 million and $6 million

•  Annually: Annual taxable revenues below $1.5 million (with the option to remit instalments)

Most small and medium-sized corporations file quarterly. The HST return and remittance are due one month after the end of each reporting period. Late remittances attract penalties starting at 1% of the balance owing for one to three days late, escalating to 10% for more than seven days late.

The Quick Method

Smaller businesses with annual taxable revenues below $400,000 may be eligible to use the HST Quick Method, a simplified approach where the corporation remits a fixed percentage of gross HST-inclusive revenue rather than tracking ITCs on every input. The percentages vary by business type.

The Quick Method reduces administrative complexity but may not produce the same net result as the regular method in all cases. A CPA can model whether the Quick Method produces a tax saving for a specific business.

When to Speak With a CPA

Setting up the HST account correctly — choosing the right filing frequency, configuring the accounting system to separate HST from revenue, and establishing an ITC documentation process — is best done before the first invoice goes out. A CPA can ensure the structure is right from day one.

Rotaru CPA helps newly incorporated businesses establish their HST compliance structure and stay current with remittances. Book a consultation to set up your HST account correctly.