Company lists · Data refreshed September 2026

Top 25 Back office accounting services based in the United Kingdom

RevenueBase identified 2,119 back office accounting services headquartered in the United Kingdom as of September 2026 and tracks 12,985 professional contacts across them, including 2,806 with verified work emails. London is the largest hub.

This list covers back office accounting services headquartered in the United Kingdom, 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 19, 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 19, 2026 86% judged on-target in blind review
2,119Companies
12,985Contacts tracked
2,806Verified emails
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The 25 largest back office accounting services based in the United Kingdom

Ranked by team size
Top 25 of 2,119 back office accounting services based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to back office accounting services: 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
1Partial evidenceHarrow, United KingdomHQ checked Sep 19, 2026201-500477 contacts →

Partial evidence

“Outbooks is a leading provider of outsourcing services to accounting and bookkeeping firms.”

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 19, 2026501-1,000322 contacts →

Indirect evidence

“At SKS, we pride ourselves on being different.”

Source: RevenueBase Database · checked Sep 19, 2026
3Partial evidenceBrighton, United KingdomHQ checked Sep 19, 2026201-500187 contacts →

Partial evidence

“Galloways is the fastest growing accounting services firm in Sussex.”

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceRushden, United KingdomHQ checked Sep 19, 2026n/a166 contacts →

Indirect evidence

“For your business to succeed.”

Source: RevenueBase Database · checked Sep 19, 2026
5Partial evidenceCarlisle, United KingdomHQ checked Sep 19, 202651-200123 contacts →

Partial evidence

“David Allen was established in 1997 and now has a team of over 150 dedicated professionals working from our offices based in Carlisle, Dalston, Dumfries, Penrith and Workington.”

Source: RevenueBase Database · checked Sep 19, 2026
6Indirect evidenceManchester, United KingdomHQ checked Sep 19, 2026201-500118 contacts →

Indirect evidence

“Focus is a UK-managed outsourcing partner with a large dedicated offshore delivery team, built and proven inside real UK retail operations before we opened it to other brands.”

Source: RevenueBase Database · checked Sep 19, 2026
7Indirect evidenceHemel Hempstead, United KingdomHQ checked Sep 19, 2026501-1,000102 contacts →

Indirect evidence

“SJD is now Caroola Accountancy!”

Source: RevenueBase Database · checked Sep 19, 2026
8Partial evidenceWembley, United KingdomHQ checked Sep 19, 202651-20096 contacts →

Partial evidence

“Affinity Outsourcing is an accountancy outsourcing company that specialises in outsourcing for Accounting Practices.”

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceGlasgow, United KingdomHQ checked Sep 19, 202651-20074 contacts →

Indirect evidence

“Streamline your business with our bespoke support services.”

Source: RevenueBase Database · checked Sep 19, 2026
10Partial evidenceLivingston, United KingdomHQ checked Sep 19, 202651-20058 contacts →

Partial evidence

“Legal Cashiering Services Payroll Services Management Accounting Statutory Accounts Credit Control Consultancy Projects The Cashroom understands that you just want to get on with…”

Source: RevenueBase Database · checked Sep 19, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 19, 202651-20058 contacts →

Indirect evidence

“We are on a mission to help accountants to grow their accountancy practice and become more profitable.”

Source: RevenueBase Database · checked Sep 19, 2026
12Partial evidencePlus X Innovation, United KingdomHQ checked Sep 19, 202651-20056 contacts →

Partial evidence

“Acenteus Accounting, legally known as Acenteus CCA Global Ltd is a UK-registered outsourced accounting and finance partner delivering secure, cloud-enabled support for…”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceLeamington Spa, United KingdomHQ checked Sep 19, 2026n/a54 contacts →

Indirect evidence

“DSL is one of the UK's leading small business accountancy firms, helping businesses grow since 1997.”

Source: RevenueBase Database · checked Sep 19, 2026
14Partial evidenceLondon, United KingdomHQ checked Sep 19, 202611-5053 contacts →

Partial evidence

“At Artifin Accountants we strive to provide a more open experience of accounting services for business owners.”

Source: RevenueBase Database · checked Sep 19, 2026
15Indirect evidenceReading, United KingdomHQ checked Sep 19, 202611-5048 contacts →

Indirect evidence

“We help reduce your stress and deal with all your company accounts and advice We handle all your payroll requirements We deal with your tax returns and pension requirements You…”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceCorby, United KingdomHQ checked Sep 19, 202651-20047 contacts →

Indirect evidence

“At Moore, our purpose is to help people thrive – our clients, our people and the communities they live and work in.”

Source: RevenueBase Database · checked Sep 19, 2026
17Indirect evidenceBeccles, United KingdomHQ checked Sep 19, 202611-5047 contacts →

Indirect evidence

“Leading providers of specialist support services.”

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 19, 202611-5044 contacts →

Indirect evidence

“In business we grow, we develop, and we change, ensure you are working with an accountancy firm that will see and understand your brand and your goals.”

Source: RevenueBase Database · checked Sep 19, 2026
19Indirect evidenceLondon, United KingdomHQ checked Sep 19, 202611-5042 contacts →

Indirect evidence

“At PSB Accountants, we put your goals and aspirations first.”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 19, 202611-5039 contacts →

Indirect evidence

“Glazers is a well-established and progressive firm of accountants based in North West London.”

Source: RevenueBase Database · checked Sep 19, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 19, 202611-5035 contacts →

Partial evidence

“We’re PennyBooks, a refreshingly modern, London based accounting firm, supporting a broad range of clients from single director freelancers through to scale up VC backed…”

Source: RevenueBase Database · checked Sep 19, 2026
22Partial evidenceLondon, United KingdomHQ checked Sep 19, 202611-5033 contacts →

Partial evidence

“Complete Accounting Solutions is a firm of dedicated individuals focussed on providing small and growing companies with support on the accounts and bookkeeping activities of their…”

Source: RevenueBase Database · checked Sep 19, 2026
23Strong evidenceChester, United KingdomHQ checked Sep 19, 2026n/a32 contacts →

Strong evidence

“Invoice finance & back office support specialists.”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceLondon, United KingdomHQ checked Sep 19, 202611-5032 contacts →

Indirect evidence

“Beany are accountants for ambitious businesses, delivering big firm expertise without the big cost.”

Source: RevenueBase Database · checked Sep 19, 2026
25Partial evidenceManchester, United KingdomHQ checked Sep 19, 202651-20029 contacts →

Partial evidence

“Finex Accounting is an outsourcing accountancy service provider.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 2,119 back office accounting services based in the United Kingdom

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Back office accounting services based in the United Kingdom at a glance

As of Sep 19, 2026
21.6%Verified-email coverage
6.1Average contacts per company
1-10Median size (employees)
17.9%Largest-city concentration · London
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
1,773
11-50
269
51-200
36
201-500
12
501-1,000
4
1,001-5,000
4

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 2,119 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 back office accounting services, 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 the United Kingdom whose own description of what they do matches “back office accounting services”. 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 back office accounting services), 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 back office accounting services, and records with no verified work email. Companies headquartered outside United Kingdom 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, 2,806 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 19, 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 back office accounting services, 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 back office accounting services are there based in the United Kingdom?

RevenueBase identified 2,119 back office accounting services headquartered in the United Kingdom 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?

Outbooks, headquartered in London, tops this list with the largest team on record.

Which city has the most back office accounting services?

London leads with 380 headquartered companies, followed by Manchester (37) and Bristol (30).

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 2,806 verified decision-maker contacts tracked across these 2,119 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 19, 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.