When Is the Corporate Tax Filing Deadline in Canada?

When is the corporate tax filing deadline in Canada? Six months after your corporation's fiscal year end. The catch is that the money is due earlier than the paperwork — two months after year end for most corporations, three for many small ones. Here is the full calendar.

A corporation must file its T2 return within six months of the end of its tax year. Unlike personal tax, there is no single national date — every corporation has its own deadline, set by its own fiscal year end, and two companies incorporated a month apart can have filing dates half a year apart.

The six months are counted with one wrinkle worth getting right. If your year end falls on the last day of a month, the deadline is the last day of the sixth month following. If your year end falls on any other day of the month, the deadline is the same numbered day, six months later. So a 31 March year end is due 30 September, while a 15 March year end is due 15 September.

That obligation applies whether or not the corporation owes anything. A company that made no money, made a loss, or did not operate at all still has to file. Dormant corporations are the single most common source of unfiled returns we see, usually because the owner assumed that no activity meant no obligation. It does not — the return is required for every tax year the corporation exists, and the CRA's records show the gap.

One more piece of practical relief: where a deadline lands on a Saturday, a Sunday or a public holiday, a return or payment received on the next business day is treated as on time. That is a courtesy for the calendar, not an extension you can plan around.

Your balance-due day — the date any remaining corporate tax has to be in the CRA's hands — is generally two months after your fiscal year end. For many small corporations it is three months.

The three-month extension is available to a Canadian-controlled private corporation that claims the small business deduction, where the corporation's taxable income together with that of any associated corporations was at or below the small business limit — $500,000 — in the current or the previous year. In practice that covers a large share of owner-managed companies, but it is a test to confirm rather than assume: a profitable year that pushes the group over the limit can quietly move your balance-due day a month earlier than last year's.

Miss that date and interest starts accruing on the unpaid balance, compounded daily at the CRA's prescribed rate. Interest is not a penalty and it is not discretionary — it runs automatically from the day after the balance was due until the day it is paid. It is also not deductible against your income, which makes it a more expensive form of borrowing than its headline rate suggests.

The sequencing this creates is the thing to internalise. For a 31 December year end, a small corporation's money is due 31 March but its return is not due until 30 June. You are therefore expected to know what you owe three months before you have to tell the CRA what you owe — which is why the books need to be substantially closed well before the filing deadline, not the week of it.

Nothing changes structurally — the same six-month and two-or-three-month rules apply — but an off-calendar year end changes which parts of the year are busy for you, and it interacts with the rest of your compliance calendar in ways a December year end does not.

A corporation may choose any fiscal year end, provided the year does not exceed 53 weeks. Many owner-managed companies pick a non-December date deliberately: to spread professional fees outside the January-to-April crush, to align with a natural trough in the business, or to sit a few months after a seasonal peak so that inventory and receivables are at their simplest. A construction company with a winter lull, for instance, may find a spring year end far easier to close than a December one — which is one of the practical points we work through with the construction businesses we act for.

The trap is that your personal deadlines do not move with your corporation's. Salary and dividends paid to you land in your personal calendar year regardless, so an owner with a June year end still has an April personal filing deadline, and remuneration decisions taken at the corporate year end have personal consequences in a different tax year. That mismatch is where most owner-manager planning errors live, and it is worth mapping both calendars side by side once rather than rediscovering it annually. Our note on the personal filing deadlines sets out that side.

Changing a year end, incidentally, is not a free choice after the fact — it generally requires the CRA's concurrence and a sound business reason, and it creates a short transitional tax year with its own set of deadlines. It is a decision to make deliberately at the start, not a lever to pull when a deadline gets uncomfortable.

The table below runs the rules through three common cases. The two payment columns show the ordinary two-month date and the extended three-month date available to an eligible small CCPC.

Read the third row carefully, because it is the one people get wrong. A mid-month year end produces mid-month deadlines all the way through — not month-end ones. Bookkeeping calendars, accounting software reminders and well-meaning advice all default to month ends, so a corporation with a 15 September year end is the one most likely to pay two weeks late while believing it paid on time.

Note also what the first row implies about workload. A December year end means the balance is due in late February or March — exactly when personal tax season is starting and when slip deadlines land. That congestion is real, and it is the main argument for choosing a different year end if the nature of your business allows it.

The late-filing penalty is calculated on the tax that was unpaid when the return was due, and it escalates for repeat offenders.

The higher rates apply where the CRA has issued a formal demand to file and the corporation has already been charged a late-filing penalty in a recent year. That combination is what turns an irritating penalty into a serious one, and it is why a corporation that has fallen behind should get current before a demand letter arrives rather than after.

Interest sits on top of all of this, compounded daily on both the unpaid tax and the penalties themselves. A corporation that files a year late with a real balance owing can comfortably end up paying a quarter more than the tax it originally owed, none of it deductible.

Here is the detail that changes what you should do when a deadline is about to slip. The late-filing penalty is a percentage of the tax unpaid at the filing deadline. If nothing is unpaid, the percentage is applied to zero — so a corporation that has paid its balance in full but files its return late faces no late-filing penalty at all.

That is not a licence to file late. Other consequences remain: interest on anything that turns out to have been underpaid, the loss of certainty about your own position, elections that must be filed with a return by its due date, and the risk of a demand to file that escalates the penalty rate on any future slip. But it does reorder your priorities when time is short.

The practical rule that follows: when in doubt, pay first and perfect the return later. If the books are not finished by the balance-due day, make a considered estimate and pay it. Overpaying is recoverable — the excess comes back on assessment or sits against the next year — and it stops interest and defuses the penalty. Underpaying by a little costs a little interest. Paying nothing while you wait for perfect numbers is the expensive option.

Getting that estimate close enough to be useful is a bookkeeping question rather than a tax one, which is why the corporations that handle this smoothly are invariably the ones whose bookkeeping is current through the year. Our corporate tax calculator will turn a draft profit figure into a reasonable estimate of the balance in a couple of minutes.

Most established corporations do not settle their tax in one payment. They pay it through the year in instalments, and each instalment has its own due date. Miss them and the CRA charges instalment interest — and where that interest is large enough, an additional instalment penalty on top.

Instalments are generally monthly, due on the last day of each month of the tax year. Eligible small Canadian-controlled private corporations may pay quarterly instead, which is a meaningful reduction in administration for an owner-managed company. Eligibility turns on a perfect compliance record, a taxable income within the small business limit for the group, and claiming the small business deduction — and a corporation that falls out of eligibility reverts to monthly, which is easy to miss.

A corporation in its first year generally has no instalment obligation, because instalments are based on the tax of the current and preceding years and there is no history to base them on. That relief is a common trap in year two: the first year's tax arrives as a single balance, and instalments for the second year begin at the same time, so a young company faces both at once. Startups are hit by this constantly — one of several cash-flow surprises we walk new companies through, alongside the ones covered in our note on corporate filing for startups.

Two smaller points. Instalments are not required where the total tax payable for the year is below a modest threshold, so genuinely small corporations may pay once and be done. And an instalment based on last year's higher income over-funds the account, which is a refund you waited a year for — a good reason to base instalments on a realistic current-year estimate where the business has slowed.

The T2 is one obligation among several, and the others do not follow your fiscal year end. Missing these is what turns a well-run company into one with a compliance file.

• T4 and T5 slips. Slips reporting salary or dividends paid to employees and shareholders are due by the end of February following the calendar year they relate to, with copies to the recipients by the same date. This is a calendar-year deadline regardless of your fiscal year end, and the penalties are per slip — cheap individually, unpleasant across a payroll. If you are paying yourself or anyone else, this belongs in a payroll process rather than a year-end scramble.
• GST/HST returns. Filing frequency depends on your revenue — annual, quarterly or monthly — and each frequency has its own deadline measured from the end of the reporting period. An annual filer's return and payment dates are not the same as its T2 dates, which surprises people every year. We cover the mechanics in our HST return work.
• Payroll remittances. Source deductions are due on a schedule set by your remitter type, most commonly by the 15th of the month following the pay. These attract their own penalties, and they are the ones the CRA pursues most energetically, because the money was withheld from someone else.
• Provincial and annual returns. Corporate registry filings — annual returns to maintain the corporation's good standing — are separate from tax filings entirely, and forgetting them can lead to dissolution rather than a penalty.

The reason to list these together is that they interlock. A December year end concentrates the T2 balance, the slip deadline and personal tax season into eight weeks; a June year end spreads them out. Neither is right or wrong, but knowing which shape your year has is the difference between a busy month and a missed date.

Filing a T2 on paper is no longer a free choice for most corporations. A corporation with gross revenue above $1 million is required to file electronically, and filing on paper when you are required to file electronically attracts its own penalty, separate from anything to do with lateness.

Below that threshold electronic filing is still overwhelmingly the better option, for the same reason it is on the personal side: an electronically filed return is processed automatically and quickly, while a paper return is keyed by hand and sits in a queue. Faster assessment means faster certainty about your balance, and faster resolution when something needs correcting.

Electronic filing also means the return is prepared in certified software, which catches internal inconsistencies before submission rather than after. A paper return with a schedule that does not tie to the main form comes back as correspondence months later, by which time interest has been running on whatever the correction reveals.

One consequence worth flagging for owner-managed companies: filing electronically requires either your own software and credentials or a representative authorised to file for you. Getting that authorisation in place before the deadline week is a small piece of administration that becomes a real problem if left late — we set out how representative authorisation works now in our note on authorising a representative with the CRA.

Three situations produce deadlines people do not expect.

The dormant or loss-making corporation. A return is still due six months after year end. There is no exemption for inactivity, and while a nil return with no tax owing generates no late-filing penalty on a zero balance, the unfiled years accumulate on your account and are the usual reason a corporation cannot get a certificate or complete a sale years later. Filing losses also has a positive purpose: a loss reported now is a loss available to carry forward against future profits, and an unfiled year is a loss you may struggle to use.

The first tax year. A new corporation's first tax year runs from incorporation to whatever year end it chooses, so it is almost always shorter than twelve months. The six-month filing rule and the two-or-three-month payment rule both run from that first year end, which can arrive much sooner than a founder expects — a company incorporated in September that picks a 31 December year end has a balance due by the following February or March.

A short tax year from a change. An acquisition of control, an amalgamation, a wind-up or an approved change of year end all end a tax year early and start a new one. Each of those stub periods is a full tax year for filing purposes, with its own return and its own deadlines, and the six-month clock on the stub period does not wait for the longer year that follows it.

In all three cases the practical failure is the same: nobody diarised a deadline because nobody realised a tax year had ended. That is worth a conversation whenever the corporation's structure changes, and it is part of what small business accounting support is for.

The instinct when a corporate return is overdue is to wait until everything is perfect. That instinct is wrong in every direction: penalties and interest accrue monthly, and the escalated penalty rate turns on having received a demand to file. Acting before the CRA writes to you is materially cheaper than acting after.

The order that works:

1. Pay something now. Even a rough estimate against the balance stops interest on the amount paid and reduces the base the late-filing penalty is calculated on.
2. File the oldest year first. Outstanding returns interact — a later year's assessment can depend on a prior year's closing figures, and losses flow forward. Filing out of order produces reassessments.
3. File everything, including the nil years. A clean, complete account is what stops escalation and what any future buyer, lender or auditor will ask for.
4. Then ask about relief. The CRA can cancel or waive penalties and interest in defined circumstances — serious illness, a natural disaster, an error on the agency's own part — through a taxpayer relief request. It is a real avenue with a real application process, not an appeal against the rules, and it is generally considered for a limited number of prior years. Where a genuine extraordinary circumstance caused the delay, it is worth making the request properly.

What relief will not do is excuse a corporation that simply did not get around to it. That being so, the cheapest available action is almost always the boring one: get current, then keep the books close enough to current that next year's estimate can be made in March rather than June. The wider habits that make this painless are the same ones we set out in our note on small business write-offs, because a company that can produce a reliable profit figure quickly can pay on time.

Three dates run a Canadian corporation's year, and they are worth writing on the wall: the balance-due day two or three months after year end, the filing deadline six months after year end, and whatever instalment schedule applies in between. Everything else in this guide is detail hanging off those three.

If you take only one operating change from it, make it this: work out roughly what you owe before the balance-due day and pay it, even if the return is weeks from finished. That single habit removes interest, defuses the late-filing penalty, and turns the filing deadline from a cliff into an administrative date. It requires nothing more exotic than books that are close to current.

And if the corporation is already behind, the calculation favours moving now rather than waiting for tidy numbers. Penalties escalate with a demand letter, and the cost of being approximately right today is far lower than the cost of being exactly right next spring.

We file corporate returns for companies across the country, from Calgary to the GTA, entirely remotely, and we map every deadline against your own year end at the start of the engagement. Fixed fees agreed before work starts, payment after the service, and our corporate tax filing fees are published so the number is clear up front. Book a free 15-minute call or ring +1 (416) 619-0068.