Company lists · Data refreshed September 2026

Top 9 Tax consulting firms based in Ottawa, Canada

RevenueBase identified 28 tax consulting firms headquartered in Ottawa, Canada as of September 2026 and tracks 452 professional contacts across them, including 178 with verified work emails. Toronto is the largest hub.

This list covers tax consulting firms headquartered in Ottawa, Canada, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 6, 2026 86% judged on-target in blind review
28Companies
452Contacts tracked
178Verified emails
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The 9 largest tax consulting firms based in Ottawa, Canada

Ranked by team size
Top 9 of 28 tax consulting firms based in Ottawa, Canada, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to tax consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceOttawa, ON, CanadaHQ checked Sep 6, 202651-200109 contacts →

“Marcil Lavallée est un partenaire engagé qui contribue activement à la réussite de ses clients en anticipant leurs besoins et en leur offrant une gamme complète de solutions…”

Source: company website · checked Sep 6, 2026
2Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 202651-20094 contacts →

“GGFL is the tax planning and accounting firm for Ottawa’s successful business people.”

Source: company website · checked Sep 6, 2026
3Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 202651-20080 contacts →

“At Baker Tilly Ottawa LLP, we provide expert tax, assurance, and entrepreneurial services to help your business grow and prosper.”

Source: company website · checked Sep 6, 2026
4Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 202611-5013 contacts →

“AI Tax Consultants specializes in delivering tax and accounting services to individuals, self-employed and corporations.”

Source: company website · checked Sep 6, 2026
5Strong evidenceOttawa, ON, CanadaHQ checked Sep 6, 202611-508 contacts →

“Vaive and Associates Professional Corporation is a tax consulting, business advisory and accounting firm.”

Source: company website · checked Sep 6, 2026
6Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 20261-108 contacts →

“Armstrong Jones LLP is an accounting firm based in Ottawa, Ontario that offers services in accounting, audit and assurance, tax planning and compliance, and a wide array of…”

Source: company website · checked Sep 6, 2026
7Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 20261-104 contacts →

“Pryor Tax Law is a boutique law firm with expertise in Canadian, U.S.”

Source: company website · checked Sep 6, 2026
8Partial evidenceOttawa, ON, CanadaHQ checked Sep 6, 20261-103 contacts →

“Blachford Tax Law represents individuals and businesses who are facing significant tax disputes with the Canada Revenue Agency.”

Source: company website · checked Sep 6, 2026
9Indirect evidenceOttawa, ON, CanadaHQ checked Sep 6, 20261-101 contacts →

“ibma Accounting is your wise choice!”

Source: company website · checked Sep 6, 2026

Showing 9 of 28 tax consulting firms based in Ottawa, Canada

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Tax consulting firms based in Ottawa, Canada at a glance

As of Sep 6, 2026
39.4%Verified-email coverage
16.1Average contacts per company
1-10Median size (employees)
414.3%Largest-city concentration · Toronto
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
21
11-50
3
51-200
4

Email recency for this list is measured across the whole Canada list rather than this city, so it is reported there. Company counts and contact totals on this page are exact for Ottawa, over 28 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among tax consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Ottawa, Canada whose own description of what they do matches “tax consulting firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names tax consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among tax consulting firms, and records with no verified work email. Companies headquartered outside Ottawa are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 178 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 6, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names tax consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many tax consulting firms are there based in Ottawa, Canada?

RevenueBase identified 28 tax consulting firms headquartered in Ottawa, Canada as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Marcil Lavallée, headquartered in Ottawa, tops this list with the largest team on record.

Which city has the most tax consulting firms?

Toronto leads with 116 headquartered companies, followed by Mississauga (64) and Calgary (58).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 178 verified decision-maker contacts tracked across these 28 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 6, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.