HST vs Income Tax: What Ontario Small Business Owners Mix Up (And How to Avoid It)

If you're a small business owner in Ontario, one of the most common (and expensive) mistakes is mixing up HST and income tax.

They're totally different. And confusing them usually leads to one of two problems:

• You spend money that was never yours (HST), or
• You don't set aside enough for tax time (income tax)

Let's make it simple.

HST vs income tax: the simplest explanation

HST (Harmonized Sales Tax)

HST is a sales tax you collect on behalf of CRA.
If you're registered, you charge HST to customers, collect it, and later remit the net amount to CRA.

Key point: HST is not your income.

Income tax

Income tax is tax on your profit.
Profit = income − expenses. Your income tax is based on your net profit for the year.

Key point: income tax depends on your profit, not your sales.

Why people get confused (Ontario small business reality)

This happens all the time:

• You invoice a client for $1,000 + HST ($130)
• You receive $1,130
• You treat the full $1,130 like “income”
• You spend it
• Then CRA wants the HST, and tax time wants income tax too

That's how cash-flow stress starts.

What you should do instead (simple system)

Step 1: Separate HST immediately (if registered)

If you are HST-registered:

• Move the HST portion into a separate account the same day you get paid

Example:

• Paid: $1,130
• HST: $130 → move to “HST savings”
• Remaining: $1,000 is business income (before expenses)

Step 2: Set aside income tax from the profit portion

Income tax is based on profit, but you can still estimate.

A simple starting point:

• Set aside 25%–35% of your business income (after HST) until you know your real numbers.

If you want to be safe, use 30% as a default estimate.

The key difference in one table

Common mistakes to avoid

• Charging HST when you're not registered (or should be registered)
• Forgetting to remit HST on time
• Not tracking ITCs (HST paid on expenses)
• Thinking “I didn't withdraw money so I won't owe income tax”
• Mixing personal and business spending (bookkeeping becomes messy fast)

Quick checklist: what to track monthly

If you want to avoid surprises, track these monthly:

• Sales (before HST)
• HST collected
• HST paid on expenses (ITCs)
• Net profit estimate
• Amount set aside for income tax

This is exactly what clean bookkeeping is for.

FAQs