Onboarding a New Tax Client: Engagement Letter → T1013 → First Filing in 4 Steps

Why onboarding makes or breaks the relationship

The first 30 days of a new client relationship is when they decide whether they made the right choice. If onboarding is smooth — clear next steps, fast turnaround, professional polish — the client trusts you with their corporate group's bookkeeping next year. If it's chaotic — emails crossing each other, "where do I send this?" confusion, two-week silence between asks — they wonder if they should have stayed with their old accountant.

Most firms have an onboarding "process" that lives mostly in the partner's head. New client comes in, partner figures out next steps, sends some emails, eventually a return gets filed. That works at 1–2 new clients per quarter. It breaks down at 5+, and during T1 season it falls apart entirely — the firm onboards a dozen new T1 clients in two months, and at least two of them have a bad first experience.

The fix is a documented 4-step workflow that's the same for every new client. Here it is.

1The engagement letter

The engagement letter is your contract. It defines scope, fees, responsibilities, confidentiality, and termination. It's also a legal protection: when something goes sideways years later, the engagement letter is what saves you (or doesn't).

What to include

• Scope of services — exactly which filings (T1 personal? T1 + GST? T2 corporate + payroll?), which tax years
• Fee structure — fixed-fee, hourly, retainer; payment terms (net 15? net 30? upfront?)
• Client and firm responsibilities — client provides accurate, complete information; firm prepares and files based on what's provided
• Confidentiality and PIPEDA-aligned consent — explicit consent to use personal information for engagement purposes; reference your privacy policy
• Document retention — how long the firm keeps records, and what happens at engagement end
• Termination — how either party can end the engagement, fees owing on termination
• For assurance engagements only — independence, reporting, and additional standards-required language

Most provincial CPA bodies publish engagement letter templates; start there and customize for your firm.

Send via e-signature

In 2026 there's no reason to print, sign, scan, and email an engagement letter. E-signature is legally valid in Canada (PIPEDA + provincial e-commerce acts) and dramatically faster. Typical flow: send via the e-signature tool, client signs on their phone within a day, signed copy is in your system automatically.

Track three statuses per engagement letter: Sent (waiting on client), Signed (we have a contract), and Counter-signed (firm has also signed). If you're not running counter-signed flows, set that up — having both signatures protects both parties.

2CRA authorization (Form AUT-01)

You can't access a client's CRA account without their authorization. The current form is AUT-01 (which replaced T1013 for individuals in 2020 and consolidated several earlier authorization forms). Many practitioners still call it "the T1013" colloquially — and CRA documentation sometimes uses both names — but the official form name is AUT-01.

What AUT-01 enables

• View the client's tax records (notices of assessment, balances, correspondence)
• File returns and correspond on the client's behalf
• Access slips already filed (T4, T5, T3) for the client through CRA
• For corporate clients, access the corporation's CRA account

How to submit it

Two paths:

• Online via CRA Represent a Client — fastest. Authorization typically activates within 5 business days. Client signs the AUT-01 (you can have them sign via your e-signature tool, then upload), or the firm submits via Represent a Client and the client confirms electronically
• Paper — slower (4–6 weeks for activation), only use as a fallback

Practical tip: get the AUT-01 signed at the same time as the engagement letter. Both can be in one e-signature envelope, both signed in one client interaction. Don't ask twice.

Pulling prior-year data

Once authorized, immediately pull the client's slip information for the prior year and the prior year's notice of assessment. The NOA contains carry-forwards (capital losses, RRSP room, donation carryforwards) that affect the current year. Doing this in week 1 saves hunting for it during preparation in week 6.

3Document collection

With the engagement letter signed and CRA authorization filed, you can now ask the client for their documents. The key word is specific.

Personalize the checklist

Don't ask for "your tax documents." Ask for a specific list of items based on what the client has told you about their situation. For new clients, this comes from the intake interview. The checklist might look like:

• 2025 T4 from (employer name client mentioned)
• T5 from (brokerage if discussed)
• RRSP contribution slip (if RRSP mentioned)
• 2024 notice of assessment (we'll pull from CRA but please confirm)
• T776 if you receive rental income (you mentioned an investment property)
• T2125 self-employment summary if applicable
• Donation receipts
• Medical expense receipts
• Spouse's information if filing jointly

For a deeper system on document collection that works at scale, see How to Stop Chasing Clients for Tax Documents.

Send through the client portal

The client portal should be the primary deposit channel. The client gets one link, uploads everything in one place, and the system shows them progress against the checklist. The firm gets organized files, no email attachments, and PIPEDA-aligned encrypted storage.

Set up automated reminders

Configure automated reminders from day one of onboarding: 7 days, 14 days, and 21 days after sending the checklist. Most clients respond by day 7. Some need the 14-day nudge. The 21-day reminder is escalation — partner attention.

4First filing

With documents in hand, prepare the return. This is the actual work — but the workflow around it is what matters for onboarding quality:

Track on the workflow board

Create the engagement card on your workflow board with stages: Documents Received → In Preparation → Partner Review → Awaiting Client Signature → E-filed. Every staff member can see where the engagement is.

Partner review is non-negotiable on first engagements

Even the best junior misses things on a return for a client they don't know yet. The first return for any new client gets a partner review pass. This is also when you catch any setup mistakes (year-end wrong, GST/HST frequency wrong, related entities not connected) that would cause problems for years to come.

Send for client signature via e-signature

T183 (e-file authorization) needs to be signed. Use e-signature — same flow as the engagement letter. Track until signed.

E-file

Submit through your tax preparation software. Save the confirmation in the client's document folder. Update workflow status to E-filed.

Send a "we're done" email — and ask for a referral

The post-filing email is a relationship moment. Send a clear summary: filed, refund/balance owing, next deadline, anything notable. Ask if the client knows anyone who might benefit from your services. New clients in their first 90 days have the highest referral conversion rate of any client cohort — they're newly excited about you. Capture it.

What this looks like end-to-end

For a typical new T1 client, the timeline:

• Day 0: Initial call. Engagement letter and AUT-01 sent for e-signature within 2 hours
• Day 1–2: Engagement letter and AUT-01 signed
• Day 2: Document checklist sent through portal. CRA authorization submitted online
• Day 3–7: Documents flow in. Reminders fire automatically
• Day 7: CRA authorization active. Pull NOA and prior slips
• Day 8–10: Return prepared
• Day 11: Partner review
• Day 11–12: T183 sent for signature; e-filed once received
• Day 12+: Welcome-aboard email with referral ask

The whole arc is roughly 12 calendar days, with about 30–45 minutes of staff time spread across them. That's what "onboarding works" looks like.

The 5 mistakes firms make in onboarding

1. Sending engagement letter and AUT-01 in two separate interactions

Combine them. One e-signature envelope, two documents, signed once. Saves the client a second interaction and saves you waiting on a second signature.

2. Not pulling prior-year NOA promptly

Prior-year NOA has carry-forwards (RRSP room, capital losses, charitable donation carry-forwards) that affect the current return. Pull it in week 1 once authorization is active. Don't wait until preparation week to discover the prior accountant carried a $40K capital loss forward that affects the current year's planning.

3. Generic document checklist

"Please send all your tax documents" doesn't work. A personalized list based on the intake conversation works dramatically better. Spend 5 minutes per new client tailoring the checklist; save 3 hours later.

4. No automated reminders

Without a system, the partner has to remember to follow up on day 7. They don't. The client forgets too. Two weeks pass. Now the engagement is at risk before the first return is even prepared.

5. Skipping partner review on first return

"It's just a T1, the junior can do it." Yes, except the junior set up the wrong year-end on the new client's corporate file because they misunderstood the intake notes, and now you'll discover it next year when the T2 deadline calculator is wrong. First-return partner review catches setup mistakes that would compound for years.

How MyCPACRM supports the full onboarding workflow

MyCPACRM connects every step of onboarding into a single flow. Client management captures the new client's profile and configuration. E-signatures handles engagement letter, AUT-01, and T183 in one or two envelopes. The client portal is the document deposit channel with personalized checklists. Automated reminders chase documents on schedule. The workflow board tracks the engagement from intake through e-file. Document management auto-files everything to the client folder. The dashboard shows partners every onboarding in flight.

The first new client your firm onboards using a real workflow is the moment the firm starts behaving like a firm instead of like a job.

Frequently Asked Questions

What is Form AUT-01 and is it the same as T1013?

AUT-01 is the current CRA form for authorizing a representative to access a taxpayer's account. It replaced T1013 for individuals as of 2020 and consolidated several earlier authorization forms. Many practitioners still call it "the T1013" colloquially; the official name is now AUT-01 for individuals and RC59 for businesses (though RC59 has also been replaced by AUT-01 paths in many cases).

How long does it take for AUT-01 authorization to take effect?

Online submissions through CRA Represent a Client typically activate within 5 business days. Paper submissions can take 4–6 weeks. The signed authorization is valid until cancelled.

What should be in a CPA engagement letter for a tax engagement?

At minimum: scope of services (which filings/years), fee structure, payment terms, client and firm responsibilities, confidentiality and PIPEDA-aligned consent, retention of documents, and termination conditions. For assurance engagements, additional independence and reporting language is required by professional standards.

Should small CPA firms use e-signature for engagement letters?

Yes — e-signature has been legally valid in Canada under PIPEDA and provincial e-commerce acts since the early 2000s, and adoption is now standard for engagement letters, T1013/AUT-01 forms, and engagement renewals. The time savings for the firm and convenience for the client are substantial.

How long should onboarding a new T1 client take?

With a streamlined system: 30–45 minutes of staff time spread across the 4 steps, over 7–10 calendar days from signed engagement to first filing ready for review. Without a system: 3+ hours of staff time and 3–6 weeks of calendar time.