Company lists · Data refreshed September 2026

Top 25 Accounting companies based in Ottawa, Canada

Name: Accounting companies based in Ottawa, Canada
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 7, 2026 111 companies tracked

This directory lists 111 accounting companies based in Ottawa, Canada, with 1,284 business contacts and 627 email addresses available as of September 2026. Across Canada, Toronto is the largest hub for this category (471 companies); Ottawa has 111.

Accounting companies provide services such as bookkeeping, financial reporting, tax preparation, auditing, payroll support, and financial advisory work for businesses and other organizations. This list covers companies that provide accounting, bookkeeping, tax, audit, payroll, or related financial reporting services to business clients. Ranked by team size, largest first. Data current as of September 7, 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 7, 2026 86% judged on-target in blind review

111Companies

1,284Contacts tracked

627Verified emails

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The 25 largest accounting companies based in Ottawa, Canada

Ranked by team size

Top 25 of 111 accounting companies based in Ottawa, Canada, ranked by team size, largest first. Data refreshed Sep 7, 2026. RevenueBase Smart Search rates how each company's information relates to accounting companies: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Welch LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	201-500	399 contacts →
	Strong evidence “Welch LLP is a Chartered Public Accounting firm that has deep roots in the communities it serves.” Source: RevenueBase Database · checked Sep 7, 2026
2	Marcil Lavallée	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	109 contacts →
	Indirect evidence “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: RevenueBase Database · checked Sep 7, 2026
3	Ggfl LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	94 contacts →
	Strong evidence “GGFL is the tax planning and accounting firm for Ottawa’s successful business people.” Source: RevenueBase Database · checked Sep 7, 2026
4	Logan Katz LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	80 contacts →
	Strong evidence “Logan Katz is a forward-thinking public accounting firm delivering high-quality, client inspired accounting, taxation, assurance and business advisory services in Ottawa and…” Source: RevenueBase Database · checked Sep 7, 2026
5	Mccay Duff LLP	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	66 contacts →
	Indirect evidence “McCay Duff LLP is a full-service Chartered Accountants Firm that has been serving the Ottawa area since 1946.” Source: RevenueBase Database · checked Sep 7, 2026
6	Lekadir LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	47 contacts →
	Strong evidence “Lekadir LLP is a Chartered Professional Accounting firm providing a full range of accounting, assurance, tax, and advisory services.” Source: RevenueBase Database · checked Sep 7, 2026
7	Connelly & Koshy Professional Corporation	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	33 contacts →
	Strong evidence “Chartered Professional Accountants licensed to practice in Ontario and Quebec with offices in Ottawa and Shawville Practice areas- Accounting - Auditing of profit oriented…” Source: RevenueBase Database · checked Sep 7, 2026
8	The Bookkeeping Bureau LTD	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	20 contacts →
	Indirect evidence “We’re a laid-back team of professionals working together to solve a tough problem.” Source: RevenueBase Database · checked Sep 7, 2026
9	Zenbooks	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	16 contacts →
	Indirect evidence “Zenbooks is your cloud accountant, tax planners and business advisers.” Source: RevenueBase Database · checked Sep 7, 2026
10	AI TAX Consultants	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	13 contacts →
	Strong evidence “AI Tax Consultants specializes in delivering tax and accounting services to individuals, self-employed and corporations.” Source: RevenueBase Database · checked Sep 7, 2026
11	Hendry Warren LLP	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	51-200	12 contacts →
	Indirect evidence “At Hendry Warren LLP our mission is to provide relevant, reliable information and advice to help our clients achieve their business goals, and offer superior client service in a…” Source: RevenueBase Database · checked Sep 7, 2026
12	Ernst & Company CPA	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	10 contacts →
	Strong evidence “Ernst & Company has been providing professional accounting services for clients in the Ottawa area since 2002.” Source: RevenueBase Database · checked Sep 7, 2026
13	Vaive And Associates Professional Corporation	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	8 contacts →
	Strong evidence “Vaive and Associates Professional Corporation is a tax consulting, business advisory and accounting firm.” Source: RevenueBase Database · checked Sep 7, 2026
14	Armstrong Jones LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	1-10	8 contacts →
	Strong evidence “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: RevenueBase Database · checked Sep 7, 2026
15	The BM Group	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	8 contacts →
	Strong evidence “The Business Management Group is a boutique accounting firm located in the heart of Westboro.” Source: RevenueBase Database · checked Sep 7, 2026
16	Bouris Wilson LLP	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	7 contacts →
	Strong evidence “Bouris, Wilson LLP is one of Ottawa-Carleton’s most respected and trusted chartered accounting firms.” Source: RevenueBase Database · checked Sep 7, 2026
17	Converge Financial INC	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	7 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 7, 2026
18	Paterson & Company	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	7 contacts →
	Indirect evidence “Similar to most CPA firms, we bring extensive income tax and financial statement preparation experience to our clients.” Source: RevenueBase Database · checked Sep 7, 2026
19	L. Zinman & Company	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	1-10	6 contacts →
	Indirect evidence “L.” Source: RevenueBase Database · checked Sep 7, 2026
20	Boyer & Boyer, CPA	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	6 contacts →
	Indirect evidence “Managing your own financial affairs is overwhelming and time-consuming!” Source: RevenueBase Database · checked Sep 7, 2026
21	Numetrica	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	1-10	6 contacts →
	Indirect evidence “Our Mission An accountant has a unique position in the world.” Source: RevenueBase Database · checked Sep 7, 2026
22	Synapse Accounting Group	Strong evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	1-10	5 contacts →
	Strong evidence “We are a cloud-based accounting firm.” Source: RevenueBase Database · checked Sep 7, 2026
23	Leslie & Macleod, Chartered Accountants Cpas	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	5 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 7, 2026
24	Ouseley Hanvey Clipsham Deep LLP	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	11-50	4 contacts →
	Indirect evidence “OHCD is a firm of Chartered Accountants that was founded in the Ottawa area in 1984.” Source: RevenueBase Database · checked Sep 7, 2026
25	Accountrain INC	Indirect evidence	Ottawa, ON, CanadaHQ checked Sep 7, 2026	1-10	4 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 7, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: accounting companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names accounting companies.
Partial evidence: Its own public description names part of accounting companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name accounting companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 111 accounting companies based in Ottawa, Canada

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Accounting companies based in Ottawa, Canada at a glance

As of Sep 7, 2026

48.8%Verified-email coverage

11.6Average contacts per company

1-10Median size (employees)

Sep 7, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

Email recency for this list is measured across the whole Canada list rather than for Ottawa, so it is reported there. Company counts and contact totals on this page are exact for Ottawa, over 111 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 accounting companies, 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 “accounting companies”. 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 accounting companies), 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 accounting companies, 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, 627 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 7, 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.

Accounting companies by metro in Canada

Frequently asked

How many accounting companies are in the directory?

The directory contains 111 accounting companies based in Ottawa, Canada as of September 2026.

How can I find contacts at accounting companies?

The directory includes 1,284 business contacts and 627 email addresses associated with the listed accounting companies.

Which city in Canada has the most accounting companies?

Toronto leads Canada with 471 headquartered companies, followed by Calgary (291) and Vancouver (221). Ottawa has 111.

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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.