New client onboarding checklist
Updated October 12, 2026
The short answer
Sign an engagement letter, get authorization to represent the client with the CRA, record their entity type, year end, GST/HST and payroll details, collect prior-year returns and access to their records, and set up their deadlines and recurring work before doing any billable work.
Paperwork first
- A signed engagement letter that defines the scope, fees and responsibilities.
- Authorization to represent the client with the CRA, through Represent a Client or the client's account, at the access level you need.
- Business number, legal name and contact details.
The details that drive their deadlines
- Entity type and province.
- Fiscal year end.
- GST/HST registration and reporting frequency.
- Payroll account and remitter type, if any.
- Whether they file T4, T5 or T3 slips.
Records and access
Ask for the last two years of returns and notices of assessment, bank and credit card access or statements, and any open CRA correspondence. Put each in the client's own folder so the next person on the file finds them in one place.
Then set it all running
With the details recorded, generate the client's deadlines and create their recurring jobs. In Clerra, adding a client with those details builds their full filing calendar automatically.
Frequently asked questions
Why record the fiscal year end at onboarding?+
Every corporate deadline is derived from it, so a wrong year end means every date is wrong.
Do I need CRA authorization for every client?+
To act for a client with the CRA, you need their authorization. It is separate from the engagement letter, and can be given online through the CRA's representative services.
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.
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