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Guide2026-06-05·6 min

Corporate tax deadlines: what small corporations should track

Guide

Canadian corporations do not all share one tax deadline. Your key dates depend on your corporation's fiscal year-end and whether you have a balance owing or instalment obligations.

That means the useful question is not "what is the 2026 deadline?" It is:

What dates should this corporation track from its year-end?

The T2 filing date

The CRA generally requires a corporation to file its T2 Corporation Income Tax Return within six months after the end of its tax year.

For example, a corporation with a December 31 year-end generally works toward a June 30 filing deadline.

If a due date falls on a Saturday, Sunday, or public holiday recognized by the CRA, the CRA may treat the filing or payment as on time if it is received or postmarked on the next business day. Always confirm the rule for your situation.

The balance-due date can be earlier

Filing the return and paying the balance are different deadlines.

For many corporations, any balance owing is due two months after year-end. Some Canadian-controlled private corporations may qualify for a three-month balance-due date if they meet the CRA's conditions.

That matters because a package can be "not filed yet" while the payment deadline is already close.

Instalments

Some corporations must pay tax by instalments during the year. A common trigger is having tax payable above the CRA threshold in prior years, but the exact schedule depends on the corporation's facts.

Do not wait until package generation to check instalments. Treat them as part of the annual review rhythm.

A practical preparation calendar

For owner-led corporations, the calendar should work backward from the filing and payment dates:

  1. Right after year-end: collect bank activity, bookkeeping exports, receipts, invoices, and statements.
  2. Before the balance-due date: review expected tax owing and cash planning.
  3. Before package generation: resolve missing receipts, shareholder loan details, asset records, and unusual transactions.
  4. Before filing: review the T2 package, GIFI mapping, notes, and filing-channel boundary.
  5. After filing: keep support records and review notes where they can be found later.

How OPTAX helps

OPTAX is built to keep deadline work attached to the preparation workflow:

  • records show what has been received;
  • evidence shows what supports a number;
  • questions show what is not ready;
  • review shows what the owner needs to check;
  • the package shows what can be inspected before CRA submission.

Official starting points:

Boundary

This article is general information, not tax advice. Confirm CRA deadlines for your corporation and consult a qualified professional for complex situations.