Pick the window before you pick the firm
The timing of the switch matters more than almost anything else about it, and the right window is just after a filing cycle closes, never just before one opens. For a corporation, that means shortly after the T2 and year-end financials are filed, when the outgoing firm's work is complete and nothing is half-built. For owners whose pain point is personal tax, it means after the spring filing season, not in March. Switching two months before a year-end forces the new firm to either rush an unfamiliar file or inherit another firm's half-finished working papers, and both options cost you money.
Some filings never pause, and they define the handover's hard constraint. HST returns, payroll remittances and instalments continue on their own schedule regardless of who your accountant is, so the transition plan has to name who files each one during the overlap. A missed remittance in the gap is the single most common way a switch actually disrupts a business, and it is entirely preventable with one shared calendar.
If you are still deciding whether to move at all, settle that first, on evidence rather than irritation. Our page on the signs you have outgrown your current accountant separates service problems worth leaving over from friction worth a conversation. A switch done for the right reasons survives the two or three mildly annoying weeks every transition contains.
The handover sequence, start to finish
A clean transition runs through seven phases, in a fixed order, and the order is doing most of the work. Notice that notifying your current accountant comes fourth, not first: you want the destination confirmed before you announce the departure, so your business never sits uncovered.
| Phase | What happens | Who does it |
|---|---|---|
| 1. Shortlist and discovery | You meet the prospective firm, describe the entities, filings and pain points, and hear how they would run the file | You |
| 2. Engagement letter | Scope, fee and start date in writing, contingent on a clean handover | New firm and you |
| 3. Predecessor communication | The new CPA, with your permission, writes to the outgoing firm asking whether there are circumstances to consider before accepting the engagement, a professional obligation for CPAs in Ontario, and the predecessor is expected to respond promptly | New firm |
| 4. Your notice and records release | You send the outgoing firm a short, civil note ending the engagement and authorizing release of your records to the new firm | You |
| 5. Records transfer | Returns, statements, schedules and continuity balances move firm to firm; you are copied, not couriering boxes | Both firms |
| 6. CRA authorizations | The new firm is authorized on your CRA accounts and the old firm's access is cancelled | New firm and you |
| 7. Onboarding review | The new firm reviews prior filings and balances, rebuilds the compliance calendar and flags anything inherited | New firm |
The predecessor letter in phase 3 deserves a word, because owners sometimes read it as bureaucracy. It is your protection. It surfaces unpaid fees, undisclosed CRA disputes or scope surprises while you can still plan around them, and it means the two professionals establish a working channel before a single deadline depends on it. A firm that skips this step is telling you something about how it runs files.
What you are entitled to take with you
Everything you gave the firm and everything you paid the firm to produce for you comes with you; the firm's internal working papers generally do not, because they belong to the firm that created them. In practice the essential package is bigger than most owners request, and requesting it completely, once, beats six follow-up emails. The detailed checklist lives on its own page, what records to request from your previous accountant, but the spine of it is:
- Filed returns and assessments for every entity, several years back, T2s, T1s, HST and payroll filings, with CRA's notices.
- Year-end financial statements and the adjusting journal entries behind them, so your bookkeeping file reconciles to what was filed.
- Continuity schedules: capital asset and CCA records, loss carryforwards, shareholder loan balances and the corporate tax accounts a future dividend or sale depends on.
- The bookkeeping data itself, including admin access if the software subscription sits in the firm's name rather than yours.
- Open correspondence: anything CRA has sent that is unresolved, and any elections or filings made on your behalf.
Two frictions come up often enough to plan for. If you owe the outgoing firm money, expect the handover to slow until the account is settled or terms are agreed, so deal with the invoice early and separately from any service complaints. And if your books live in a desktop file or a subscription the firm controls, ownership of that data is a phase-4 conversation, not a discovery you make after access disappears.
Keep CRA pointed at the right firm
CRA authorizations are the switch's highest-stakes detail, because whoever holds representative access sees your correspondence and can act on your accounts. The new firm gets authorized through CRA's representative system, you approve it, and the outgoing firm's authorization gets cancelled the same week, for every entity and every program account: corporate tax, HST, payroll, and your personal account if the firm handled that too. Leaving an old firm authorized for years after a switch is astonishingly common and entirely without upside.
In-flight CRA matters need an explicit owner. If the outgoing firm is mid-way through answering a review, an audit query or an objection it filed, decide deliberately whether it finishes that matter or hands it over immediately, and put the answer in writing. Splitting a live CRA file between two firms with no named lead is how deadlines get missed, and CRA does not accept the transition as an excuse. As a rule: matters rooted in the old firm's own work usually transfer, since you want your representative's only interest to be yours; routine matters days from completion usually finish where they started.
What a good first ninety days looks like
Onboarding is where you find out whether the switch was worth it, and a serious firm treats it as a review, not a data import. Within the first month or two, expect the new CPA to re-perform a sanity check on recent returns, verify the continuity balances it inherited, confirm elections and carryforwards, check that the compliance calendar covers every entity, filing and instalment, and give you a short written list of what it found, ranked by dollars and deadline. We keep a full checklist on what a new CPA should review during onboarding, and it is a fair test to hand any firm you are interviewing.
Sometimes the review finds real problems, a missed election, a wrong balance, unreported income, and this is the moment switches justify themselves, because inherited errors are cheapest the day they are found. If that happens, the path is laid out in what happens when your previous accountant made a tax error: correct first, pursue accountability second, and let the new firm run both tracks. This is also where the commercial reality of CRA support and corporate compliance work shows: an Ontario CPA who owns your calendar, your correspondence and your corrections is the difference between compliance as a system and compliance as luck.
By day ninety the steady state should be visible: filings landing early rather than on deadline, questions answered in days, and a calendar you can see. If the first ninety days feel like the old firm with new letterhead, say so while the relationship is young.
The facts that change the answer
The sequence above fits most owner-managed businesses, but six facts stretch or compress it, and they are worth stating plainly at the discovery stage:
- Your year-end date. It defines the natural window; a switch planned around it is calm, and one planned against it is not.
- Open CRA matters. A live audit or objection needs a named lead before anything else moves.
- The state of the books. Clean cloud books transfer in days; a desktop file behind on reconciliations adds a cleanup phase before the new firm can stand behind anything.
- How many entities. A holdco, an opco and a family trust triple the authorizations, records and calendar entries, not the difficulty, but the checklist length.
- Who runs payroll and HST. Filings the old firm processed need a continuity owner from the first day of the gap.
- Outstanding fees or friction. Money owed or a soured relationship slows the records phase, so it gets settled or scheduled first.
For owners who want the destination to be a complete outside finance function, books, filings, reporting and advisory under one roof, that is what our Ongoing Financial Partnership is, and the transition plan above is exactly how we begin one. Scope and fee arrive in writing after a free 15-minute discovery call, before you give notice to anyone.
