Corporate Tax Instalments in Canada: 2026 Guide

A Canadian corporation must pay tax by instalments when its total taxes payable — federal plus provincial — were more than $3,000 in either the current or the previous tax year. Instalments are normally monthly, though eligible small Canadian-controlled private corporations (CCPCs) may pay quarterly. You calculate them using one of three CRA methods and pay the remaining balance shortly after year-end. This guide explains who pays, how to calculate, the deadlines, and the Alberta-versus-federal split.

Who has to pay instalments

As of the 2026 tax year, your corporation must remit instalments if its net tax owing exceeds $3,000 in either the current or the prior tax year. The $3,000 test looks at combined federal and provincial Part I tax (plus certain other taxes). If your tax owing is $3,000 or less in both years, you are exempt and simply pay the full amount when the balance is due.

Two important carve-outs:

• New corporations are not required to make instalments in their first tax year — there is no prior year to base them on — but they should still budget for the year-end balance.
• A short tax year prorates the instalment requirement.

Monthly or quarterly?

The default instalment frequency is monthly. However, the CRA allows eligible small CCPCs to pay quarterly, which eases cash flow. To qualify for quarterly instalments as of 2026, the corporation must generally:

• be a CCPC claiming the small business deduction;
• have taxable income (with associated corporations) at or under the $500,000 small business limit in the current or previous year;
• have taxable capital within the allowed limit; and
• have a clean compliance history — no overdue returns or amounts owing in the prior 12 months.

If the corporation falls offside any condition (for example, it loses access to the small business deduction), it reverts to monthly instalments.

The three calculation methods

The CRA gives you three methods to compute instalments, and you may use whichever produces the lowest total — provided your estimate holds up. The trade-off is risk: the lower-payment method usually relies on an estimate that, if wrong, triggers instalment interest.

Worked illustration (monthly, stable income). Suppose a CCPC's federal-plus-Alberta tax was $24,000 last year and is expected to be similar this year. Under Method 2, the corporation pays $2,000 per month for 12 months. If it qualified for quarterly instalments, it would instead pay $6,000 per quarter. Under Method 1, if the corporation expects only $18,000 this year, it could pay $1,500 per month — but if actual tax comes in at $24,000, the CRA charges instalment interest on the shortfall.

The safest default for a stable business is Method 2 (prior-year base), because it cannot be second-guessed on the estimate. Method 1 saves cash when you can credibly forecast a down year.

Deadlines

Note the gap: the return is due six months after year-end, but the money (the balance after instalments) is due in two or three months. Paying late on the balance — not just the instalments — triggers arrears interest.

Alberta vs federal: two separate streams

This is where Alberta differs from most of Canada. The CRA administers corporate tax for the federal government and for most provinces, so a BC or Ontario corporation pays a single combined instalment to the CRA. Alberta does not participate in that arrangement.

As of 2026, an Alberta corporation pays two separate instalment streams:

1. Federal instalments and balance to the CRA (on the T2), and
2. Alberta instalments and balance to Alberta Tax and Revenue Administration (TRA) under the Alberta Corporate Tax Act (filed on the AT1).

The Alberta instalment rules mirror the federal logic — the $3,000 threshold, monthly-versus-quarterly eligibility, and the three calculation methods all apply on the Alberta side — but the payments and filings are made to TRA, not the CRA. Quebec is the only other province with its own separate corporate tax administration. Practically, an Alberta corporation must track and remit two sets of instalments and reconcile two balances at year-end.

Avoiding instalment interest and penalties

The CRA charges instalment interest, compounded daily at the prescribed rate, on instalments paid late or for too little. If that interest exceeds $1,000, an additional instalment penalty can apply (broadly, half the amount by which the interest exceeds the greater of $1,000 and 25% of the interest that would apply with no instalments).

Two practical defences:

• Pay early or overpay. Interest earned on early or excess instalments (contra interest) offsets interest charged on deficient ones, so front-loading payments protects you against an estimate that proves too low.
• Reconcile mid-year. If income is trending above forecast under Method 1, increase the remaining instalments before year-end rather than discovering a shortfall after the fact.

For a sense of the underlying tax these instalments fund, use our corporate tax calculator. For the broader Alberta corporate picture — rates, the AT1, and the small business deduction — see our Alberta corporate tax guide, and browse common questions in our corporate tax FAQ hub.

How RN Canada helps

RN Canada is an accounting and advisory firm with offices in Edmonton and Vancouver, led by Ozgur Duymaz, Ph.D., CPA (Canada), ACCA (UK), CMA (US). We determine whether your corporation must pay instalments, select the calculation method that minimizes both cash outflow and interest risk, manage the two separate Alberta and federal payment streams, and keep instalment interest and penalties off your account. See our bookkeeping and tax filing service to have your corporate instalments and year-end balance handled with the deadlines tracked for you.