HMRC R&D Enquiry Process & Timeline
Understanding the enquiry process helps you prepare effectively and set realistic expectations. Here's what typically happens from receiving the letter to resolution.
Typical Enquiry Timeline
Enquiry Letter Received
You receive a letter from HMRC opening an enquiry into your R&D claim. The letter specifies which accounting period is under review, what information HMRC requires, and the deadline for your response (usually 30 days).
Forward to Your Adviser
Send the letter to your R&D adviser or accountant immediately. If you don't have specialist support, contact Innovation Plus for an urgent review. The 30-day clock is already running.
Initial Response Deadline
Your response must be submitted by this deadline. Extensions are possible but must be requested before the deadline expires, with good reason.
Information Exchange
HMRC reviews your response and may request additional information, ask follow-up questions, or request a meeting (video or in-person). This stage can involve multiple rounds of correspondence.
HMRC Officer Review
The HMRC officer reviews all information and forms their view. This is often the longest stage as it depends on HMRC workload.
Meeting (If Required)
Some enquiries require a meeting to discuss technical details. This may involve your technical staff, your R&D adviser, HMRC compliance officer, and HMRC technical specialist.
Enquiry Concluded
The enquiry concludes with one of several outcomes: full acceptance (claim stands), partial reduction, full rejection, or discovery assessment (previous years opened).
Key Deadlines
- 30 days – Standard response deadline
- Before deadline – Request extension if needed
- 3-6 months – Typical pre-payment check duration
- 6-18 months – Full enquiry duration
Need Help?
We can review your enquiry letter and advise on the best approach within 24 hours.
Get Expert HelpInformation HMRC Commonly Requests
Being prepared with this documentation can significantly speed up the enquiry process.
Technical Documentation
- Detailed narrative explaining R&D activities
- Evidence of technological uncertainty at project start
- Explanation of how uncertainties were resolved
- Project specifications and technical documents
- Email correspondence about technical challenges
- Test results and iteration records
Personnel Information
- Competent professional qualifications
- CVs of key technical staff
- Organisational chart
- Staff time allocation records (timesheets)
- Employment contracts
Financial Documentation
- Detailed cost breakdown by project
- Payroll records for claimed staff
- Subcontractor invoices and contracts
- Consumables receipts and calculations
- Grant documentation (if applicable)
Methodology Evidence
- How time allocations were determined
- Basis for apportionment calculations
- Process for identifying qualifying activities
Need Help Navigating the Process?
Our experienced team has handled hundreds of HMRC enquiries. We know what works.