Cartmill Stewart & Co.

What Cartmill Stewart & Co. does

Cartmill Stewart LLP, operating commercially as Cartmill Stewart & Co., is a chartered accounting firm headquartered at 48 Bachelors Walk, Lisburn, Northern Ireland, providing professional accounting, compliance, and advisory services to small businesses in the region. Founded in 2014 by partners Claire Stewart and Gilbert Cartmill, the firm operates with 1–10 employees and is a member firm of Chartered Accountants Ireland, operating under a UK Limited Liability Partnership structure.

The firm delivers six core services: Bookkeeping & Payroll, Business Advisory, Business Startups, Cloud Accounting, Tax Planning & Compliance, and a Client Portal. Its technology-enabled service model is anchored by certified advisor partnerships with three cloud accounting platforms — Xero, QuickBooks, and FreeAgent — enabling implementation, training, and ongoing support across heterogeneous client software preferences. An Engager-based client portal supports document exchange and communication, while distribution relies on a tax-focused blog with multiple posts in November 2025, an email newsletter sign-up, and a WhatsApp business contact channel.

Revenue is generated on a professional services model through recurring monthly advisory engagements (bookkeeping, payroll, ongoing business advisory, ongoing tax) supplemented by project-based work (business startups, cloud accounting implementation, one-off tax planning). Pricing is quote-based rather than publicly disclosed. Go-to-market is regional and sales-led via website inquiries, phone, email, WhatsApp, and in-person consultation at the Lisburn office, targeting new and experienced Northern Ireland business owners needing tax compliance support, financial record keeping, and cloud accounting technology adoption.

Name

Cartmill Stewart & Co.

Legal name

Cartmill Stewart LLP

Website

https://cartmillstewart.co.uk

Company type

Private

Founded year

2014

Operating status

Operating

Headcount range

1–10 employees

Short description

Cartmill Stewart LLP is a chartered accounting firm in Lisburn, Northern Ireland, offering cloud-enabled bookkeeping, payroll, tax, and advisory services to small business owners across the region.

Ownership category

akta.pro rank

Product category

Accounting Services

NAICS

Accounting, Tax Preparation, Bookkeeping, and Payroll Services (54121), Payroll Services (541214), Offices of Certified Public Accountants (541211), Accounting, Tax Preparation, Bookkeeping, and Payroll Services (5412)

akta.pro primary industry

Accounting & Bookkeeping Services (BPAHABAC)

Keywords

• Chartered accounting services
• Cloud accounting advisory
• Bookkeeping payroll services
• Tax planning compliance
• Small business advisory

Headquarters

HQ city

Lisburn

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D, Infrastructure

Revenue model

1. Professional Accounting Services: Revenue generated through professional accounting services including bookkeeping, payroll, business advisory, tax planning and compliance, and cloud accounting implementation and support. Services are provided on a recurring advisory basis with project-based engagements for startups and business setup.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

Cartmill Stewart & Co. is a chartered accounting firm (trading name for Cartmill Stewart LLP, founded 2014) based in Lisburn, Northern Ireland. The firm delivers bookkeeping, payroll, business advisory, business startup support, tax planning and compliance services, alongside cloud accounting implementation and advisory using platforms such as Xero, QuickBooks, and FreeAgent.

Product overview

Cartmill Stewart LLP is a chartered accounting firm offering a unified suite of professional accounting, compliance, and advisory services. The firm provides six core service offerings: Bookkeeping & Payroll, Business Advisory, Business Startups, Cloud Accounting, Tax Planning & Compliance, and a Client Portal. The Cloud Accounting service serves as a technology-enabled foundation, leveraging partnerships with Xero, QuickBooks, and FreeAgent platforms to deliver setup, training, and ongoing support. The other services complement this core offering by providing bookkeeping, payroll, business advisory, startup support, and tax planning capabilities under one advisory relationship.

Differentiator

Problem solved

Functional benefit

Products and services

• Bookkeeping & Payroll

Segments1 record

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration3 records

Partnerships

Three partnerships are on record, tiered core.

• XerocoreTechnology or IntegrationCertified Xero Advisor partner providing Xero cloud accounting software setup, training, and ongoing support to clients. The firm implements Xero as part of their technology-enabled accounting solutions.
• QuickBookscoreTechnology or IntegrationCertified QuickBooks Advisor partner offering QuickBooks accounting software implementation, training, and ongoing support services to business clients.
• FreeAgentcoreTechnology or IntegrationCertified FreeAgent Advisor partner providing FreeAgent cloud accounting software setup, training, and support services.

Recent moves4 records

Expansion highlights3 records

Emerging players

• Crunch: Online-only UK accounting and tax service for freelancers, contractors, and small businesses with cloud accounting at its core. Represents the digital-first competitive pressure facing traditional local chartered firms.
• Coconut: UK fintech offering self-employed and small business banking plus integrated bookkeeping and tax tools. Adjacent competitor in the cloud-bookkeeping stack that threatens to disintermediate traditional accountants like Cartmill Stewart.

Broad incumbents

• KPMG Northern Ireland: Big Four accounting firm with an established Belfast office offering tax, advisory, and audit services. Operates in the same NI market but serves larger and more complex clients than Cartmill Stewart's SMB focus.
• Grant Thornton Northern Ireland: Mid-tier accounting and advisory firm with NI presence serving dynamic mid-market and SMB clients. Overlaps with Cartmill Stewart on tax, advisory, and cloud-accounting services but at larger scale.
• BDO Northern Ireland: Global accounting and advisory network with an NI practice serving mid-market and SMB clients. Comparable tax, accounting, and advisory offerings but with significantly greater resources and brand recognition.
• Moore (formerly Moore Stephens NI): Top-20 UK accounting network with an established Northern Ireland office covering accounting, audit, tax, and advisory. Comparable service scope but materially larger scale and broader geographic reach.

Direct peers

• CavanaghKelly: Chartered accountants and business advisors based in Northern Ireland with a comparable full-service SMB offering spanning bookkeeping, payroll, tax, and cloud accounting. Closest like-for-like competitor in the same NI regional market.
• PKF-FPM: Chartered accountants and business advisors with a strong Ireland/Northern Ireland presence offering accounting, tax, and cloud-enabled advisory to owner-managed businesses. Comparable on services and chartered-accountant positioning.
• Cloud Accountancy (UK): UK-based cloud-first accountancy firm specializing in Xero, QuickBooks, and FreeAgent for SMBs. Directly comparable on the technology-enabled advisory positioning that Cartmill Stewart emphasizes.
• Whitelaw Reid: Chartered accountancy firm serving SMBs in Northern Ireland with compliance, tax, and advisory services. Directly comparable on size, geography, and service mix to Cartmill Stewart.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat2 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/cartmillstewart
• Facebookfacebook.com/cartmillstewart
• LinkedInlinkedin.com/company/cartmillstewart

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Cartmill Stewart & Co.