GST/HST for Service-Based Businesses in Ontario: A Plain-English Guide

HST is one of the most misunderstood obligations for small business owners in Ontario. Many entrepreneurs register late, file incorrectly, or overlook input tax credits available to them.

When Do You Need to Register for HST?

You must register once revenues exceed $30,000 in any single calendar quarter or in four consecutive calendar quarters. This applies to taxable revenues, not profit. Registration obligations begin immediately upon crossing the threshold, no grace period exists. Service businesses often reach this point quickly, particularly after incorporation.

What Is the HST Rate in Ontario?

Ontario's HST rate is 13%, comprising 5% federal GST and 8% provincial component. On a $1,000 invoice, you collect $1,130 total. Importantly, the collected HST belongs to the CRA, not your business.

Input Tax Credits: The Part Most People Miss

Registered businesses can claim Input Tax Credits for HST paid on expenses. If you paid $1,300 in HST on business software, office supplies, and professional services this quarter, you deduct this from collected HST. This often results in refunds, especially during high-expense startup phases.

Filing Frequency: Annual, Quarterly, or Monthly?

CRA assigns filing frequency based on revenue:

• Annual: under $1.5 million
• Quarterly: $1.5 million to $6 million
• Monthly: over $6 million

Common HST Mistakes for Service Businesses

Five critical errors show up repeatedly: missing registration deadlines, forgetting incorporated entities need separate HST numbers, overlooking ITCs, confusing exempt versus zero-rated supplies, and late filing (which incurs 1% per month on late HST remittances plus a flat penalty).

HST for Incorporated vs. Unincorporated Businesses

Incorporated businesses require separate HST registration numbers from personal accounts, a frequently overlooked step during incorporation.