We identify qualifying R&D activity, evidence it against the DSIT Guidelines, and quantify the qualifying expenditure behind it — building claims that hold up under HMRC compliance checks, not just claims that get filed.
Why PSS Tax
R&D Tax Relief Built Around Your Business. Backed by Expertise. Driven by Compliance.
PSS Tax is a UK R&D tax relief specialist with offices in London, Manchester and Hampshire. We assess technical uncertainty against the DSIT Guidelines, quantify qualifying expenditure, and file Additional Information Forms under HMRC’s merged RDEC scheme, retaining audit-defence documentation for every claim we submit.
What You May Experience with Another R&D Firm
Templated Claim Narratives
Boilerplate technical reports that do not map to your actual projects, competent professionals or qualifying expenditure.
No Support Between Claims
A single-submission relationship, leaving you to track legislative change such as the merged RDEC scheme and overseas expenditure restrictions alone.
Payment Before Benefit, Enquiry Billed Separately
Fees due before HMRC pays out, with compliance-check defence charged as a separate engagement.
With PSS Tax
Project-Level Assessment
Each project tested individually for technological uncertainty, with qualifying expenditure apportioned from payroll, subcontractor and consumable records.
Support Across Claim Cycles
Eligibility guidance, qualifying expenditure planning and legislative updates between submissions, not only at filing.
Success Fee, Enquiry Defence Included
Fee agreed in writing before work begins, with HMRC compliance-check support included in the standard R&D service.
The PSS Tax Difference
Technical Expertise. Financial Precision. Advice You Can Trust.
Technical & Financial Expertise
Technical consultants and qualified accountants assess the same claim: one tests the technological advance, the other apportions qualifying expenditure across payroll, EPWs and subcontractors.
Evidence-Led Approach
Every claim built from project records, competent-professional interviews and costed timesheets, producing audit-defence documentation retained for the enquiry window.
Compliance at Every Stage
Eligibility, qualifying activities and expenditure tested against CTA 2009 Part 13 and the DSIT Guidelines before the Additional Information Form is filed.
Client-Centric Service
A named consultant throughout the claim, direct access to the people writing your technical narrative, and no call-centre handoffs.
UK-Based, Nationwide Support
Offices in London, Manchester and Hampshire, with technical interviews conducted on site or remotely across the UK.
Long-Term R&D Partnership
Multi-year claim cycles, advance-notification deadlines tracked on your behalf, and forward planning so future projects are documented as they happen.
How We Help
Expert R&D Support, From Eligibility to Submission
Client Experiences
Trusted by Businesses. Proven by Experience.
Verified reviews from UK businesses we have prepared and defended R&D claims for, including clients who have been through an HMRC compliance check with us.
Rob and his team are the consummate professionals and absolute experts in their field. We have been in safe hands every step of the way with R&D, including a compliance check. I would strongly recommend PSS and their services.
R&D Tax Relief · Compliance Support
Matthew
Verified Google Review
We've been using PSS-Tax to handle our R&D tax relief claims for the past few years and couldn't recommend them highly enough. Rob and the team have been brilliant throughout, they really took the time to understand our business and get under the skin of what we do, which made the whole process much easier than we expected. As a mechanical contractor, identifying and evidencing R&D isn't always straightforward, but Rob guided us through it in a way that felt manageable and made a lot of sense. Professional, knowledgeable and great to deal with. We'll definitely be continuing to use PSS-Tax going forward.
R&D Tax Relief · Technical Expertise
Tom Anderton
Managing Director
DSR Mechanical Services Ltd
Verified Google Review
I was recommended to use PSS by a good friend who had previous good experiences with them, so I engaged with Rob & Callum for their services. I have been very impressed with the service I received. I would certainly recommend to anyone else in the future!
Eligibility Assessment · Long-Term Client
Kio Marketing
Managing Director
Kio Marketing
Verified Google Review
Ready to find out whether your projects qualify for R&D tax relief?
Speak with our R&D specialists about your projects, qualifying expenditure and whether a retrospective claim is still in date.
Our Track Record
The Numbers Behind PSS Tax
R&D tax relief demands more than knowing the rules. It requires technical understanding, financial expertise, and experience built across real projects, real qualifying expenditure and real HMRC compliance checks.
1,500+
R&D Claims Supported
£90m+
Qualifying R&D Expenditure Assessed
70+
HMRC Enquiries Supported & Won
80+ Years
Combined Relevant Expertise
Supporting UK businesses across construction, engineering, manufacturing, software, technology and professional services.
Our Team
Meet the R&D Specialists Behind the Claims
Contact us
Let’s Talk About Your R&D
Whether you are considering a first claim, want a second opinion on eligibility, or need to know whether a retrospective claim is still in date, speak to our team. We will assess your projects against the qualifying criteria and give you a direct answer at no cost.
FAQ
Your R&D Tax Relief Questions, Answered
Direct answers on eligibility, qualifying expenditure, fees, HMRC compliance checks and working with your existing accountant.
How does the R&D tax relief claim process actually work from start to finish?
Does R&D tax relief apply to my industry, or only to science and technology companies?
How do I know if my company’s projects actually qualify for R&D tax relief?
What happens if you decide my projects don’t qualify for R&D tax relief?
How much does it cost to make an R&D tax relief claim through PSS Tax?
What happens if HMRC opens a compliance check into my R&D claim?
What information do you need from us to prepare an R&D tax relief claim?
Can you work alongside our existing accountant rather than replacing them?
How do I get started with an R&D tax relief claim?
How far back can I claim R&D tax relief?
Do I need to notify HMRC before making a first R&D claim?