How to track every client's tax deadlines
Updated October 12, 2026
The short answer
Record each client's entity type, fiscal year end, GST/HST frequency and payroll setup once, then derive every deadline from those fields instead of typing dates. Practice-management software can do this automatically and roll dates past weekends and holidays.
Why spreadsheets break
A spreadsheet works at 20 clients and fails quietly at 100. Dates are typed by hand, weekends and holidays are remembered or forgotten, and nothing tells you when a client's situation changed, such as a new GST/HST registration or a payroll account.
What to record for each client
- Entity type: individual, sole proprietor, corporation, partnership or trust.
- Fiscal year end (not every corporation uses December 31).
- GST/HST registration and reporting frequency.
- Payroll account and remitter type.
- Whether the client has T4, T5 or T3 slips to file.
- Province, which can add provincial filings and holiday exceptions.
Work back from the due date
A deadline is the end of the work, not the start. Set a start-by date, a ready-by date and a due date for each filing, so the work is staged across the weeks before it is due rather than stacked in the final days.
What good software does
Look for software that computes the dates from the client record, moves dates past weekends and holidays, shows one firm-wide list of what is due sorted by urgency, and lets a filing be marked filed in one step. Clerra does this for Canadian firms: add a client once and the CRA and provincial calendar is built for you.
Frequently asked questions
How many deadlines does a typical client have?+
A corporation with GST/HST and payroll can have dozens in a year: the T2, monthly or quarterly GST/HST returns, payroll remittances, T4 and T5 slips, and instalments.
Should deadlines be typed in or calculated?+
Calculated. Typed dates drift when a client's year end, GST/HST frequency or payroll schedule changes, and they miss weekend and holiday roll-overs.
Let Clerra track these for every client.
Add a client once and their full CRA and provincial calendar is built automatically. Weekends and holidays are handled.
Start free for 14 days