T3 filing deadline: 90 days after year end (March 31, 2027 for 2026)

T3 due dates by year end

The rule sits in paragraph 150(1)(c) of the Income Tax Act: an estate or trust files within 90 days from the end of its year laws-lois.justice.gc.ca. The CRA applies it to the return and to any balance owing canada.ca. Here's what that gives for the year ends you'll actually see.

When the 90th day falls on a Saturday, Sunday or a public holiday the CRA recognizes, the return is on time if the CRA receives it, or it's postmarked, by the next business day canada.ca. A payment gets the same grace if the CRA receives it or a Canadian financial institution processes it by that next business day canada.ca.

Watch the leap year. February 2028 has 29 days, so 90 days after December 31, 2027 is March 30, 2028. Diarize March 31 out of habit and the return is a day late.

What is due on the same day

The return isn't the only thing on the 90 day clock. The T3 return, the T3 slips, any NR4 slips and the T3 and NR4 summaries all go in within 90 days after the year end, and the balance owing is due the same day canada.ca. The slips must also reach each beneficiary's last known address within those 90 days.

Schedule 15 (beneficial ownership information) rides with the return. For taxation years ending in 2025, the CRA said every trust other than a bare trust had to file a T3 return including Schedule 15 by March 31, 2026, unless specific conditions are met canada.ca.

If the trust also pays nonresidents, see the NR4 deadline for the slip side. Instalments are separate from the 90 day balance: since 2016, only a graduated rate estate is exempt from trust instalments, and the 2025 T3 guide says the CRA continues not to assess penalties or interest when a trust underpays them canada.ca.

Estates with a year end other than December 31

A graduated rate estate can pick any year end up to one year after the date of death, and the executor sets it on the first T3 return canada.ca. Other trusts generally use December 31 canada.ca. A testamentary trust that isn't a graduated rate estate also uses December 31, including in the year it ceases to exist.

Worked example: your client died June 10, 2025, and the estate chose May 31 as its year end. The first T3 covers June 11, 2025 to May 31, 2026. Count 90 days from May 31: June has 30, July 31, August 29, so the 90th day is August 29, 2026. That was a Saturday, so the return and payment were on time through Monday, August 31, 2026.

GRE status ends 36 months after death. When the year end isn't the anniversary of death, you file one more T3 for the stub between the third year end and the 36 month date canada.ca. In the example, that stub runs June 1, 2028 to June 10, 2028.

When the estate distributes its last property, its tax year ends on that date. The final return and any balance owing are due 90 days after the final distribution canada.ca. Get a clearance certificate before you distribute.

Deemed year ends that move the date

Some events end a trust year early, and the 90 days run from that deemed year end rather than December 31.

The CRA lists these on its estate due dates page canada.ca. A mutual fund trust can also elect a December 15 year end, which moves its 90 days back two weeks, as the table above shows canada.ca.

Late filing: the penalty math

A late T3 with tax owing draws 5% of the unpaid tax plus 1% for each full month late, up to 12 months canada.ca. With no tax unpaid, the alternative penalty is $25 a day, from a minimum of $100 to a maximum of $2,500. Compound daily interest runs on any unpaid amount from the day after the due date canada.ca.

A trust that already had a late filing penalty in the three prior years and then gets a demand to file faces 10% plus 2% a month, up to 20 months.

If you're still waiting on investment slips at the deadline, don't hold the return. The CRA says to estimate the income, file on time, and send the slips with a letter asking for an adjustment if the amounts differ canada.ca.

Bare trusts for 2025 and 2026

As of October 2026, the CRA does not expect bare trusts to file a T3 return with Schedule 15 for taxation years ending in 2025. It has given advance notice that certain bare trusts may need to file starting with 2026 year ends, under changes proposed in Bill C-15 that the CRA will administer before enactment canada.ca. Details are on bare trust filing requirements.