Corporate Tax Installments: When CRA Expects You to Pay Throughout the Year

Most business owners know they have to pay corporate income tax. Fewer know that CRA may expect you to pay it throughout the year in installments, not just in one lump sum after your year-end. If you are not aware of the installment requirement, you can find yourself owing interest charges on a tax bill you thought was handled.

This is an educational overview of how corporate tax installments work in Canada. Your accountant can tell you exactly what applies to your corporation based on your specific situation.

What Corporate Tax Installments Are

When a corporation owes a meaningful amount of corporate income tax in a given year, CRA generally requires that tax to be paid in installments throughout the following tax year rather than as a single payment at the end. The logic is simple: CRA wants tax revenue flowing in regularly, not all at once after the year closes.

The installment requirement applies when a corporation's net tax owing exceeds $3,000 in either the current or one of the two preceding tax years. This threshold has been in place for many years. If your corporation is growing and you recently crossed into meaningful profitability, installments may now apply to you for the first time.

What Owners Get Wrong and Why It Costs Money

The most common mistake is assuming that paying the full balance owing by the balance-due date eliminates any installment obligation. That is not how it works. If installments were required and were not made during the year, CRA will still charge installment interest on the amounts that should have been paid, even if the full balance is paid on time at year-end.

Installment interest is calculated at the prescribed rate, which changes quarterly and is set by CRA. It is not a huge rate, but it is avoidable interest that serves no purpose. For a corporation owing $50,000 in corporate tax, missing installments for a full year can add several hundred to over a thousand dollars in interest depending on the rate environment.

The second mistake is not planning for installments when a corporation has a strong first year. If your corporation had a breakout year and owes significantly more tax than prior years, your installment schedule for the following year may increase substantially. Not anticipating this is a cash flow planning problem.

The CFO Perspective

Installments are fundamentally a cash flow planning issue. The tax is owed regardless of whether installments are made. The question is whether you want to make smaller payments throughout the year or hold the cash and pay it all at once.

For most owner-operated businesses, I think of installments as a forced cash reserve. You are setting aside tax as you earn it, which means the cash is not available to spend on something else. That discipline is actually useful. The alternative, accumulating a large tax liability and paying it in one shot, requires holding a large cash balance throughout the year anyway if you are managing cash well. Otherwise you face a sudden, large outflow that disrupts planning.

A corporation I worked with had a very profitable year and then a slow first quarter the following year. When installments came due based on the prior year's earnings, they were making large payments out of a cash position that had tightened. The installments themselves were correct and legally required. But the timing was painful because no cash reserve had been maintained. The fix was a quarterly tax reserve practice going forward.

How CRA Calculates the Installment Amount

CRA provides three acceptable methods for calculating installment payments. Using any of these methods correctly protects you from installment interest even if the actual tax owing ends up different.

The first method is based on the current year's estimated tax. You estimate what you will owe for the current year and pay it in equal installments. This is the most accurate but requires a reasonable mid-year estimate of your tax position.

The second method uses the prior year's actual tax. You simply pay the same total amount you owed last year, spread over the required installment schedule. This is straightforward if last year's tax is known.

The third method is a hybrid: use two years back for the first two installments and the prior year for the remaining installments. CRA publishes the formula for this approach.

If you use one of these methods in good faith and your actual tax owing ends up higher, CRA will not charge installment interest on the underpayment. The key is using a recognized method, not guessing.

When Installments Are Due

For Canadian-controlled private corporations that qualify as small business corporations, installments are generally due monthly on the last day of each month throughout the tax year. The exact schedule depends on the corporation's specific situation. Your accountant can confirm the schedule that applies to you.

The balance of tax owing after installments is generally due two or three months after the corporation's tax year-end, depending on its status under the Income Tax Act.

What to Do About It

1. Ask your accountant whether installments apply to your corporation. The $3,000 threshold and the two-year lookback mean this question has a definitive answer for your specific situation. Do not assume either way.
2. If installments are required, set up a tax reserve account. Open a separate savings account and move the estimated monthly tax amount into it each month. This prevents the cash from being spent and makes installment payments straightforward.
3. Confirm the installment method your corporation will use. If your profits are lower this year than last, using the current-year method saves you cash during the year. If profits are higher, using the prior-year method may be easier to administer. Your accountant can model both.
4. Put installment due dates in your calendar. Missing a payment is an avoidable cost. Set a recurring calendar reminder one week before each due date.
5. Review your installment estimate mid-year. If your business is materially ahead or behind where you expected, update your estimate and adjust installments accordingly. CRA allows this and it prevents over- or under-payment from becoming a cash flow problem at year-end.

Corporate tax installments are not complicated, but they catch business owners off guard because nobody explains the rule until the interest notice arrives. Ask your accountant now so you are not discovering this mid-year. If you want to integrate tax planning into your broader cash flow management, book a free call at peterxiacpa.com/book.

Next step: browse the free small business tax deduction guide.