Ontario Law Firm Compliance Calendar — 2026

By: Keith Hill Jr.

Ontario law firms operate under three overlapping compliance systems: CRA, Law Society, and LAWPRO. Outlined below is the base 2026 calendar every firm should be aware of.

Monthly Deadlines

15th of every month — Payroll remittances:

CPP, EI, and income tax withheld from the prior month must be paid to CRA.

Example: December 2025 payroll is due January 15, 2026.

25th of every month — Trust reconciliations

All trust bank accounts must be reconciled within 25 days of the month-end.

Eg. December 2025 trust reconciliations are due January 25, 2026.

Last day of the month — Monthly HST filers

Monthly HST returns are due the month after the reporting period.

Eg. December 2025 HST is due January 31, 2026.

Early-Year Compliance

February 28, 2026 — T4 & T4A

2025 slips must be issued to staff and filed with CRA.

Because February 28, 2026 is a Saturday, the effective deadline shifts to the next business day, which is March 2, 2026, under CRA’s weekend rule.

March 31, 2026 — LSO Annual Report

All licensees must file their 2025 Annual Report.

NEW: Client Contingency Plan is due

April 30, 2026 — The Big Deadline

Four separate obligations fall on this date:

• Transaction levies (Q1) – January to March

• Quarterly HST (Q1) – January to March

• Transaction levy exemptions – if you do not practice real estate or civil litigation

• Annual HST payment – for December 31, 2025, year-end firms

Annual HST Filers (Dec 31 Year-End)

• Payment due: April 30, 2026

  
  

(Note: April 30 applies only to sole proprietors. Corporations must pay their annual HST by March 31, which is three months after a December 31 year-end.)

• Return due: June 15, 2026

Quarterly Filings

July 31, 2026

• Q2 Transaction Levies

• Q2 Quarterly HST

October 31, 2026

• Q3 Transaction Levies

• Q3 Quarterly HST

Non-Calendar Year Firms

Annual HST filers

Payment and filing are due three months after fiscal year-end.

Example: April 30, 2026 year-end → July 31, 2026.

Corporate tax returns

Due six months after fiscal year-end.

Example: April 30, 2026 → October 31, 2026.

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Keith Hill Jr. is the President of Bookkeeping Matters Inc. (BMI), providers of legal bookkeeping and compliance support to law firms across Ontario and beyond. With more than 15 years of experience in legal accounting and as a former Legal Accounting professor, Keith also leads BMI’s training and education initiatives, helping law firms and bookkeepers understand trust and matter-centric accounting and audit readiness.

For assistance with legal bookkeeping support or training, contact Bookkeeping Matters Inc. at info@bookkeepingmatters.ca, 1-800-893-2820, or visit www.bookkeepingmatters.ca.

© 2026 Bookkeeping Matters Inc. All rights reserved. Reproduction with credit permitted.