Knowledge bank
HMRC, enquiries & compliance
What an enquiry looks like and how to answer one.
9 answers
These answers cover what HMRC can do once a claim has been filed: the checks it runs at volume, the enquiry process, its information powers, penalties, and the routes for challenging a decision.
For the whole process in one place, start with what actually happens when HMRC opens an R&D enquiry. If a letter has already arrived, how to read an HMRC compliance check letter explains what it is asking, and HMRC enquiry support explains how Vantage can help.
- Can HMRC reopen my R&D claim after the enquiry window has closed? Only if you were careless or deliberate, or if a well-informed officer couldn't have spotted the problem from what you disclosed. A discovery assessment isn't a second chance for HMRC to look harder.
- How do I apply for HMRC advance assurance on my R&D claim? Two services, two routes. Targeted assurance covers one area via a short online form; full claim assurance covers the whole claim, for genuine first-time claimants, via a Government Gateway form.
- Is HMRC introducing an advance clearance system for R&D claims? Not yet. What exists is an advance assurance pilot running to May 2027 — one of three options a 2025 consultation considered. A fully binding pre-claim system is still undecided.
- What can HMRC require me to provide during an R&D enquiry? HMRC can formally require information and documents reasonably needed to check your claim. You can appeal most requirements within 30 days — but not for your statutory records.
- What happens if HMRC opens an enquiry into my R&D claim? Essential read HMRC opens an enquiry by formal notice, usually within a year of filing, asks questions or requests information, then issues a closure notice you can appeal within 30 days.
- What happens if I disagree with an HMRC decision on my R&D claim? You can ask HMRC to review its own decision, or notify the appeal straight to the tax tribunal. Both routes carry strict 30-day deadlines, and mediation can run alongside either.
- What is a volume compliance check on my R&D claim? HMRC risk-assesses every R&D claim and formally checks around one in six. Most checks are resolved by correspondence, but some claims are removed by a 'correction notice' you can reject.
- What penalty could apply if my R&D claim turns out to be wrong? None, if you took reasonable care — being wrong isn't careless. Penalties run 0% to 100% of the tax lost, and HMRC must explain why your behaviour was careless or deliberate, not just assert it.
- What standards does HMRC expect from my R&D tax adviser? From 18 May 2026, paid tax advisers, including on R&D claims, must register with HMRC and pass a fit-and-proper test. Professional body members are also bound by a separate, more detailed code.
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