Every LimestoneGrey engagement follows the same path: a scoping call, a clear eligibility view, parallel technical and financial workstreams, filing handled by us as HMRC-registered tax agents, and support that continues after submission. The fee is agreed before any work starts, and if HMRC opens an enquiry, enquiry support is part of the engagement as standard.
Step 1: scoping call
We start with a conversation about what your company builds, where the technical difficulty sits and what your numbers look like. From that call you get an honest view: whether your work looks like qualifying R&D, which scheme applies, and roughly what a claim could be worth. If we do not think you qualify, we tell you on that call and you have lost nothing but half an hour.
Step 2: deadlines and scheme position first
Before any drafting, we check the compliance clock. First-time claimants (and companies that have not claimed in the previous three years) must submit a claim notification within six months of the end of the period of account, and missing that window invalidates the claim entirely. We also confirm your scheme position: the merged scheme for most companies, or ERIS if you are a loss-making SME whose relevant R&D expenditure is at least 30% of total relevant expenditure.
Step 3: the technical workstream
We interview your competent professionals, the people who actually wrestled with the science or the code. Those conversations establish the advance sought, the uncertainties faced and the project boundaries, framed against the DSIT definition HMRC applies. We then draft the technical narrative and check it back with your team, so the narrative HMRC reads is one your engineers would recognise.
Step 4: the financial workstream
In parallel, we build the cost side: staff time apportionments, externally provided workers, subcontractors, consumables, software, data and cloud. Each category has its own rules, set out on our qualifying costs page, and we apply the correct treatment rather than a flat percentage guess. We also test the PAYE cap and any grant or contract complications before they become problems.
Step 5: filing, handled by us
We are registered with HMRC as tax agents, so we do not hand you a pack of numbers and leave the filing to someone else. We prepare the Additional Information Form, which is mandatory for every claim and must be submitted before or with the CT600, and we submit the corporation tax return containing the claim ourselves, or amend the return if it has already been filed. Our preference is to own the whole sequence from first interview to submission, because sequencing errors are one of the easiest ways for a valid claim to fail. If you have an accountant, they keep their role: year-end accounts and wider tax planning carry on as normal, and we keep them informed at every step. Many accountants refer this work to us for exactly that reason; see our page for accountants.
Step 6: submission and what happens after
Once you have reviewed and approved everything, we submit and track the claim with HMRC. If HMRC opens a compliance check, handling the response is part of the original engagement. Our approach to enquiries, how far that support extends and what to expect from one, is set out on our HMRC enquiries page.
How long does a claim take?
It depends mostly on how quickly information flows. Clean cost records and available technical staff make for a fast claim; missing records slow it down. We agree a timetable at the start, built around your filing deadlines and any notification window, and we keep you informed at every stage rather than going quiet for months.
What we need from you
Three things: access to the people who did the technical work, cost information (payroll, subcontractor invoices, grant and customer contracts), and timely review of drafts. We keep requests specific and batched, because you have a company to run.
What about fees?
Our fees are aligned to outcomes and agreed before work starts. There are no hidden costs, and enquiry support is included as standard. We will set out the exact fee for your situation at the end of the scoping call.
Ready to start? Get in touch and we will book the scoping call.
Written by Lisa James. Last reviewed July 2026.
