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  2. How ForrestBrown adds to a top 40 UK accounting firm’s existing R&D tax relief service

How ForrestBrown adds to a top 40 UK accounting firm’s existing R&D tax relief service

Old Mill logo

Every client I’ve referred has loved ForrestBrown’s way of working. It’s a great addition to Old Mill’s client service.

Aisha Perrott AAT CTA, R&D tax specialist, Old Mill


As a large accounting and financial advisory firm, many of Old Mill’s clients undertake innovative projects that qualify for R&D tax relief. Old Mill has a sophisticated internal R&D offering and most claims can be handled in-house. However, some are highly complex and require specialist insight.


ForrestBrown’s sector specialists and tax advisers work with specific Old Mill clients on a needs basis and only when referred to us. These services allow Old Mill to enhance its expertise when needed.


Working in partnership with ForrestBrown, Old Mill provide clients with a tailored service offering that ensures they receive access to the right industry and technical experts at the right time.

Old Mill logo

There are all sorts of R&D tax advice arrangements available to companies. Among others, there are regulated specialist R&D tax consultancies (like ForrestBrown), chartered accountancy firms with in-house R&D tax services (like Old Mill) and unregulated R&D tax firms.

Old Mill is one of the UK’s top 40 largest accounting firms. As such, it has some of this country’s leading tax specialists and advisers among its staff. Old Mill specialises in owner-managed businesses across all sectors.

As part of its services, Old Mill offers R&D tax relief advice in-house. Aisha Perrott AAT CTA is one of the leaders of the R&D offering within Old Mill and she is a Corporation Tax and R&D Specialist.

Why Old Mill works with ForrestBrown

With a wealth of experience in-house, Old Mill deals with R&D tax claims end to end in most instances. However, there are exceptions.

The nature of this incentive means that sometimes R&D projects will be highly technical. Alongside this, HMRC has recently changed its approach to the incentive. Scrutiny of R&D tax claims – software companies have been receiving HMRC nudge letters, for instance – are at an all-time high.

This creates a highly challenging situation for even the most experienced tax advisers. As Aisha notes, she’s a tax adviser, first and foremost. While she can familiarise herself with what a client is doing in most instances, there’s a limit to what a non-sector specialist can grasp.

“The language used in a lot of these projects isn’t layman-friendly. That’s where specialist input is very valuable,” Aisha explains.

ForrestBrown’s sector expertise offers Old Mill extra insight where appropriate. When a project is highly technical or complex, “it is useful to be able to obtain a second opinion on grey areas and have access to sector specialists when needed, to enhance our offering” according to Aisha.

HMRC R&D tax enquiries

Sometimes, Old Mill calls ForrestBrown in to help answer questions HMRC may have about a client’s claim. HMRC enquiries into claims prepared by Old Mill are rare. When they do occur, software enquiries can be challenging, according to Aisha.

“HMRC uses its internal software specialists to examine these claims,” Aisha explains. “So there’s a higher risk.” In one example where ForrestBrown helped an Old Mill client, HMRC challenged a single sentence in the company’s claim document as part of the enquiry.

HMRC claimed the technology in question already existed. Working alongside our software specialists, ForrestBrown’s tax advisers were able to prove to HMRC that the technology in question did not exist at the time.

Find out more about R&D tax relief in the software sector.

Colleagues and partners

“It’s nice to talk to ForrestBrown as if you’re our colleagues,” Aisha says. “I speak to staff at ForrestBrown quite frequently and you guys feel a part of my team. Everyone’s so nice and it’s such a good chat.”

This familiarity and collegiality make nuanced conversations around when it is appropriate to refer work far simpler. ForrestBrown’s consultancy is flexible and we deal with our accounting partners and clients on a personal level.

“Mostly it’s software claims, but we’re confident enough in ForrestBrown’s service that we might use you on an ad-hoc basis.” Aisha says. “Overall, every client I’ve referred has loved ForrestBrown’s way of working. It’s a great addition to Old Mill’s client service.”

The partnership goes both ways, as well. Recently, ForrestBrown approached Old Mill to collaborate on a joint offering to a prospective client. We quoted for the R&D tax relief claim and Old Mill quoted for patent box and R&D allowances. Working together, we won the work despite competing against the Big Four.

ForrestBrown thinks: Specialist R&D consultancy for accounting firms

Our work with Old Mill exemplifies the flexibility in our service offering. What makes R&D tax relief complex is how nuanced and sometimes open-ended it can be. In that same spirit, we try to offer a specialist R&D consultancy service that aligns with what clients and their accountants require.

Whether that’s resolving a tricky HMRC enquiry, working with specialists to define project boundaries or simply helping an accountant deal with a time crunch during the busy season.

Situations arise and circumstances change, whatever R&D tax partner you choose should adapt its service as you require (not the other way around).

We’d love to learn more about your accounting firm

Whether you’re already delivering R&D tax relief claims or not, ForrestBrown is completely flexible. We’re happy to help you with a specific piece of advice, one R&D tax credit claim – or all of your claims!