IR35 Shield

Case study

Anderson Anderson & Brown


About Anderson Anderson & Brown

Anderson Anderson & Brown (AAB) is one of the UK’s leading chartered accountancy and business advisory firms, providing a broad range of services to businesses from small and medium-sized enterprises (SMEs) through to global corporations.

Headquartered in Aberdeen, a large portion of AAB’s client base operate in the oil and gas sector, which is heavily populated by contractors. As a result of the extension of the off-payroll legislation to the private sector, AAB is now tasked with conducting IR35 status assessments and managing ongoing compliance for each individual contractor engaged by many of its clients.

Anderson Anderson & Brown


Overwhelming demand for resources

AAB has an IR35 team consisting of 15 staff, four of whom are qualified to undertake contract reviews. However, its experts have historically only managed compliance for individual contractors, as required by the original IR35 legislation.

More than 70 of AAB’s clients now require assistance with off-payroll compliance, each with contingent workforces ranging from 15 to over 850 personnel. Each individual contract requires a status assessment, while most clients expect AAB to monitor engagements to ensure ongoing compliance. This is an impossible task for a small team adopting manual processes.

Several of AAB’s clients are also locked in status disputes with contractors. Many contractors have assessed their own status using HMRC’s Check Employment Status for Tax (CEST) tool, arriving at an ‘outside IR35’ determination with no accompanying evidence to allay client concerns regarding tax liability risk.

Overwhelming demand for resources


Turning to automation

With an overwhelming workload that cannot be satisfied using manual processes, AAB adopts IR35 Shield Manager as its off-payroll compliance solution. IR35 Shield Manager enables AAB to meet client demand by carrying out accurate status assessments in volume, while monitoring and managing individual client accounts and engagements from a single dashboard.

The service also provides the transparency that CEST lacks. IR35 Shield’s status assessments invite both client and contractor to provide relevant input and, when completed, come accompanied with a Status Determination Statement (SDS) explaining the bearing of each individual answer on the overall outcome.


Improved capacity & simplified negotiations

AAB reports a range of significant practical and commercial benefits since adopting IR35 Shield Manager, including:


Substantially increased capacity, enabling AAB to accommodate all clients and conduct thousands of accurate IR35 status assessments.


IR35 Shield’s status assessments have effectively minimised the prevalence of status disputes between clients and contractors, with contractors significantly more receptive to ‘inside IR35’ outcomes.


AAB’s off-payroll consultancy offering has also benefitted from the insights provided by IR35 Shield’s additional features, which it uses to inform compliance advice issued to clients.

“IR35 Shield has enabled us to carry out accurate status assessments in bulk, evaluate contract terms and working practices, and satisfy clients and contractors through collaborative assessments. These, along with the additional insights and features provided, have proven invaluable for our service offering.”

Steven Fraser -

“We enjoy working with market-leading firms like AAB by providing the scalability they need to service their clients in conjunction with their valuable tax and legal expertise. Their valuable feedback helps us refine our offering, continuing to help us set the standard and make IR35 Shield the professional’s choice.”

Dave Chaplin - CEO, IR35 Shield


The obvious challenge for companies tasked with administering off-payroll compliance for multiple contingent workforces is volume. However, accuracy and transparency are also crucial to maintain an effective compliance operation while avoiding conflict. IR35 Shield Manager provides all this along with valuable compliance insights and is most importantly trusted by contractors to deliver fair and unbiased assessments.

over 150,000 assessments

Using our assessment technology

over 20 years

Over 20 years’ experience at the cutting-edge of IR35

since 2009

Built in 2009 and expertly refined to align with current IR35 case law