Company lists · Data verified August 2026

Top 25 Accounting services outsourcing companies based in the United Kingdom

There are 2,727 accounting services outsourcing companies headquartered in the United Kingdom (RevenueBase, August 2026). RevenueBase tracks 16,272 professional contacts across them, including 3,427 with verified work emails and 666 with mobile numbers. London is the largest hub.

This list covers accounting services outsourcing companies headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

2,727Companies
16,272Contacts tracked
3,427Verified emails
666Mobile numbers
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The 25 largest accounting services outsourcing companies based in the United Kingdom

Ranked by team size
Top 25 of 2,727 accounting services outsourcing companies based in the United Kingdom, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#CompanyHQEmployeesContactsVerified emails
1OutbooksLondon201-50047539
2CohesiveCroydon501-1,00036026
3SKS Business ServicesLondon501-1,000321217
4GI OutsourcingLondon201-500317168
5Obox Solution LTDLondon201-50013212
6Initor Global UKLondon51-20010843
7DebitamLondon51-20010330
8SJD AccountancyHemel Hempstead501-1,0001022
9Paperchase Business Services LTDLondon Croydon501-1,00010018
10Rayner Essex LLPSt Albans51-2009772
11Affinity Outsourcing LimitedLondon51-2009632
12More Than AccountantsManchester51-2009018
13Sapphire Info Solutions P LTDLondon51-2008828
14Base Practice Support LTD Baseline Practice Support Smc-Pvt LTDLondon51-2007519
15Isosceles FinanceCambridge51-2006818
16Affinity Associates LimitedWembley201-5006430
17The Accountancy PartnershipWirral51-2006333
18StellaripeLondon51-2005740
19Acenteus Accountingn/a51-200543
20Adler ShineLondon51-2005338
21Green & PurpleCambridge51-2004432
22Accountsbytes Private LimitedRugby51-200433
23Moore Northern Home Counties LimitedStevenage51-2004014
24AscendantLondon201-5003926
25Jump AccountingLondon51-2003414

Showing 25 of 2,727 accounting services outsourcing companies based in the United Kingdom

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Accounting services outsourcing companies based in the United Kingdom at a glance

As of Aug 28, 2026
1-10Median size (employees)
LondonLargest hub · 543 HQs
666Contacts with mobile numbers
28Emails re-verified in last 30 days

Companies by employee count

1-10
2,081
11-50
433
51-200
58
201-500
18
501-1,000
7
1,001-5,000
5

Accounting services outsourcing companies by metro

MetroCompanies
Accounting services outsourcing companies in London543
Accounting services outsourcing companies in Manchester60
Accounting services outsourcing companies in Bristol38
Accounting services outsourcing companies in Birmingham33
Accounting services outsourcing companies in Nottingham26
Accounting services outsourcing companies in Liverpool25
Accounting services outsourcing companies in Glasgow22

How this list was built

Source
The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion
Companies whose own business descriptions match “accounting services outsourcing companies”, with match quality audited by blind human judging, and headquartered in the United Kingdom.
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
Contact records re-verify on a rolling cadence; 28 contacts on this list were re-verified in the last 30 days.
Refresh
Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many accounting services outsourcing companies are there based in the United Kingdom?

There are 2,727 accounting services outsourcing companies headquartered in the United Kingdom as of August 2026 (RevenueBase).

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 accounting services outsourcing companies?

London leads with 543 headquartered companies, followed by Manchester (60) and Bristol (38).

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 3,427 verified decision-maker contacts tracked across these 2,727 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.