Alberta Tax Deadlines: Filing, Instalments, and Penalties

For the 2025 tax year, most Alberta residents must file their personal income tax return and pay any balance owing by April 30, 2026. Self-employed filers and their spouses get until June 15, 2026, to submit the return, but any tax owing is still due April 30. Alberta corporations, trusts, and GST registrants run on separate schedules described below, and missing any of these dates starts penalties and interest the next day.

Personal Filing and Payment

Alberta’s personal income tax is administered by the Canada Revenue Agency, not by the province.1Alberta.ca. Personal Income Tax You file a single T1 covering both federal and Alberta tax, and both are due on the same day.

The June extension only covers the paperwork. Interest starts running May 1 on anything unpaid, so a self-employed filer who expects a balance should estimate what’s owed and pay by April 30, then use the extra weeks to finalize the return. When a deadline falls on a Saturday, Sunday, or a public holiday recognized by the CRA, a return received or postmarked the next business day counts as on time.3Canada Revenue Agency. When to File Your Corporation Income Tax Return

Quarterly Instalments for Individuals

If your net tax owing tops $3,000 in the current year and also topped $3,000 in either of the two previous years, the CRA expects quarterly instalments rather than a single April 30 payment.4Canada Revenue Agency. Who Has to Pay – Required Tax Instalments for Individuals This catches many self-employed Albertans, landlords, and investors whose tax isn’t withheld at source.

The four instalment dates are March 15, June 15, September 15, and December 15. Farmers and fishers follow a different rule, with a single payment due December 31.5Government of Canada. Required Tax Instalments for Individuals Missing an instalment or underpaying produces instalment interest, and once that interest passes $1,000 for the year, a separate instalment penalty is added on top.6Canada Revenue Agency. Interest and Penalties on Late Taxes – Personal Income Tax

RRSP Contribution Deadline

The RRSP deadline doesn’t match the tax filing deadline, and it matters if you’re using contributions to reduce what you owe on April 30. To claim a deduction on your 2025 return, you must contribute by March 2, 2026.7Canada Revenue Agency. Important Dates for RRSPs, HBP, LLP, FHSAs and More A contribution made after that date applies to the 2026 tax year, not 2025.

Alberta Corporate Deadlines

Alberta is one of the few provinces that collects its own corporate income tax. The province’s Tax and Revenue Administration handles the AT1 separately from the federal T2, so an Alberta corporation manages two filings on independent timelines.

Filing and Payment

The AT1 is due within six months of the corporation’s fiscal year-end. A December 31 year-end means a June 30 filing deadline. Payment runs on a shorter clock: most corporations must pay any balance owing within two months of fiscal year-end.8Alberta.ca. Corporate Income Tax

Canadian-controlled private corporations get a longer payment window. A CCPC can defer full payment to the end of the third month after fiscal year-end if it meets any one of these tests:

  • It claims the Alberta small business deduction and has taxable income of $500,000 or less in the current year.
  • It claimed the small business deduction and had taxable income of $500,000 or less in the immediately preceding year.
  • Its Alberta corporate tax payable or first instalment base is $2,000 or less.8Alberta.ca. Corporate Income Tax

Monthly Instalments

Most Alberta corporations pay their provincial tax in equal monthly instalments on or before the last day of each month during the tax year, with any remaining balance due on the balance-due day. CCPCs that meet the conditions above are exempt from monthly instalments entirely. Non-CCPCs are also exempt if their Alberta tax or first instalment base is $2,000 or less, and new corporations (other than those formed by amalgamation) skip instalments in their first tax year.8Alberta.ca. Corporate Income Tax

Trusts and GST/HST

A T3 Trust Income Tax and Information Return is due within 90 days of the trust’s tax year-end, and any balance owing is due within that same 90 days.9Canada Revenue Agency. When to File Your T3 Return Most trusts use a December 31 year-end, which puts the practical deadline at March 31, though certain trusts such as graduated rate estates may have different year-ends.10Canada Revenue Agency. Filing a Trust’s T3 Return

GST/HST filing frequency depends on annual taxable supplies. Businesses at $1.5 million or less file annually, those between $1.5 million and $6 million file quarterly, and those above $6 million file monthly.11Canada Revenue Agency. Make Changes to Your GST/HST Account Monthly and quarterly filers submit the return and remit collected tax within one month after the reporting period ends. Annual filers get three months after their fiscal year-end.12Canada Revenue Agency. Businesses Have Different Filing and Payment Deadlines

If the Taxpayer Died During the Year

When someone dies, the legal representative files a final return, and the deadline depends on the date of death:p>

  • Death between January 1 and October 31: final return due April 30 of the following year.
  • Death between November 1 and December 31: final return due six months after the date of death.

If the deceased or their spouse was self-employed, the filing deadline shifts to June 15 of the following year for deaths between January 1 and December 15, or six months after death for deaths between December 16 and December 31. Any balance owing is still due by April 30 to stop interest from accruing.13Canada Revenue Agency. Prepare Tax Returns for Someone Who Died: Filing and Payment Due Dates

What Missing a Deadline Costs

Late filing with a balance owing is expensive. The penalty structure is the same for personal and corporate returns: 5% of the unpaid balance at the filing deadline, plus 1% for each full month the return stays outstanding, up to 12 months.6Canada Revenue Agency. Interest and Penalties on Late Taxes – Personal Income Tax A return filed a full year late costs 17% of the balance in penalty alone, before interest.

The penalty doubles for repeat offenders. If the CRA issued a demand to file and assessed a late-filing penalty against you in any of the three previous tax years, the rate jumps to 10% of the unpaid balance plus 2% per full month, up to 20 months.14Canada.ca. Avoiding Penalties Both conditions must apply. A prior late filing alone doesn’t trigger the elevated rate without a formal demand.

If you’re owed a refund, there’s no late-filing penalty. The penalty is a percentage of a balance owing, and if that balance is zero, the penalty is zero. Filing late still delays your refund and can hold up benefit payments like the GST/HST credit and the Canada Child Benefit.

Interest runs separately from penalties and starts the day after the payment deadline. The CRA’s prescribed rate on overdue personal and corporate tax is 7% for mid-2026 and is updated quarterly.15Canada Revenue Agency. Interest Rates for the Third Calendar Quarter Alberta’s Tax and Revenue Administration charges its own debit rate on unpaid provincial corporate tax, also 7% for 2026.16Alberta.ca. Tax, Levy, and Prescribed Interest Rates A late-paying Alberta corporation therefore faces interest from both the CRA on its federal balance and TRA on its provincial balance.

Asking for Relief on Penalties and Interest

The CRA has discretion to cancel or waive penalties and interest even when they were correctly applied. Relief generally covers three situations: extraordinary circumstances such as a natural disaster or serious illness that prevented timely filing, errors or delays caused by the CRA, and financial hardship that makes payment impossible.17Canada Revenue Agency. Cancel or Waive Penalties and Interest at the CRA Requests are typically made on Form RC4288 and are limited to the 10 calendar years before the year you apply.

Relief isn’t automatic, and it won’t reduce your underlying tax bill. If you missed a deadline for a legitimate reason, the CRA evaluates each case on its own facts, and documenting the connection between your circumstances and the missed date strengthens the request.