GST/HST Filing in Canada: A Simple Guide (and Mistakes to Avoid)

GST/HST is one of those things that is easy to put off and procrastinate on. No one wakes up excited to file it. And honestly, that is completely normal.

But when it is done wrong, it can cost money, interest, time, and a lot of unnecessary stress. From what I see, most issues do not come from the filing itself. They come from everything before it.

Before filing, pause for a moment

Before you open CRA, your numbers should already be clear. If you are searching for figures while you are filing, that is usually where mistakes begin.

Here is what you need to have ready:

1. 1
   Total sales (before tax)

   This is your revenue without the GST/HST added on top. Make sure you are not including the tax you collected as part of your income.
2. 2
   GST/HST collected

   The total tax you charged your customers during the period. This is what you will remit to CRA.
3. 3
   Business expenses and ITCs

   Input Tax Credits (ITCs) are the GST/HST you paid on your business expenses. You can claim these back, which reduces what you owe.
4. 4
   Correct reporting period and CRA access

   Know whether you are filing monthly, quarterly, or annually, and have your CRA My Business Account ready before you start.

A simple example

If $113,000 came in, that does not mean $113,000 in sales. If that total includes $13,000 HST, then your actual sales are $100,000 and the tax collected is $13,000. The same logic applies to your expenses: look at what GST/HST you actually paid on them.

Sales tax is not your money. It is collected on behalf of CRA. A simple habit: set aside 20 to 30% from each payment into a separate account. That way, filing day is not a shock.

Deadlines matter more than people expect

Even if nothing happened during the period, you still need to file. Missing a deadline means interest and possible penalties, even if the amount owing is small.

Filing Frequency	When the Return Is Due
Monthly	One month after the end of the reporting period
Quarterly	One month after the end of the quarter
Annual (most businesses)	Three months after your fiscal year end
Annual (self-employed)	Return due June 15, but any balance owing is due April 30

Common mistakes to watch for

1. 1
   Meals: only 50% is claimable

   Business meals are a common area where people claim the full amount. CRA only allows 50% of meal and entertainment expenses.
2. 2
   Vehicle expenses: business portion only

   If you use your car for both personal and business trips, only the business portion qualifies. Keep a mileage log.
3. 3
   Wrong tax rate

   The rate depends on the province where the supply was made. Not every transaction is 13% HST.
4. 4
   Missing receipts

   Without a receipt, the ITC claim can be denied. A photo of every receipt in one place is all it takes.
5. 5
   Late filing

   Even a small late balance triggers interest from CRA. File on time even if you cannot pay in full right away.

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At the end of the day

GST/HST filing does not have to be complicated. It becomes stressful when things are unclear going in. If something does not feel right before you file, it is better to check first. Submitting incorrect numbers costs more to fix later.