HMRC R&D enquiry: cashflow impact and finance routing
By Oliver Mackman · Reviewed 2026-05-11
You submitted an HMRC R&D tax credit claim and received an enquiry letter rather than the expected refund. The enquiry pauses any expected refund payment and may extend the cashflow gap by 6-18 months while HMRC reviews.
What this is
An HMRC enquiry into an R&D claim is a formal review process where HMRC asks for additional documentation or challenges aspects of the claim. Triggered by claim-specific factors (size of claim, sector, claim methodology) or by general HMRC R&D compliance focus areas. Enquiries can be limited (specific questions about specific elements) or comprehensive (full claim review). Resolution time varies from 3 months for clean limited enquiries to 18+ months for complex comprehensive reviews.
What happens if you do nothing
Cashflow: any expected R&D refund is paused until enquiry resolution. For businesses that had counted on the refund for working capital, this creates immediate pressure. Operational: the R&D claim consultant who prepared the claim usually handles the enquiry response; if the original claim was prepared in-house or by a less-experienced adviser, specialist R&D defence counsel may be needed. Future-claim impact: an enquiry doesn't automatically affect future claims but the resolution outcome (claim approved as-is, reduced, or rejected) sets a precedent for the company's subsequent claims.
Options, in order
- Engage the R&D claim adviser immediately. The 30-day response window matters; missing it can escalate enforcement.
- Apply for R&D advance finance against the expected (post-enquiry) credit value. Triver and specialist R&D-advance lenders engage with enquiries-in-progress at reduced advance rates.
- Working-capital flexi-loan from iwoca or Funding Circle to bridge the operational cashflow gap independent of the enquiry outcome.
- For tech / SaaS businesses, recurring-revenue lending from Triver or Growth Lending often fits better than R&D advance because the underwriting doesn't depend on the enquiry resolution.
- If the enquiry indicates likely claim rejection, plan for the cashflow shortage as a structural issue not a timing issue. Engage finance early before stress crystallises.
Which UK lenders engage
- · Triver and specialist R&D-advance lenders engage with enquiries-in-progress at reduced advance rates (typically 50-70% of expected credit value vs 70-80% on uncontested claims).
- · Growth Lending for revenue-trajectory-led working capital independent of the R&D claim.
- · iwoca and Funding Circle for clean-credit working-capital flexi-loan.
- · Specialist tech / SaaS lenders that read R&D enquiry as routine rather than as a red flag.
HMRC-specific notes
HMRC has materially tightened R&D claim scrutiny since 2023. The Compliance Operations programme increased enquiry rates on small-and-medium claims significantly. Common HMRC focus areas: contractor cost classification, qualifying-activity assessment for software development, externally-provided-workers documentation, group-claim aggregation. Cleaner claim documentation (contemporaneous project notes, technical-uncertainty memos, qualifying-activity logs) materially reduces enquiry risk on future claims.
Do not do this
- · Ignore the enquiry letter. Missing the response window escalates enforcement and damages future claim chances.
- · Make defensive concessions on claim elements that are correctly claimed. Specialist R&D defence advice matters; under-claiming on enquiry response is a common error.
- · Take an MCA against expected refund. The factor rate vs uncertain timing math is structurally damaging.
- · Submit the next year's R&D claim while the previous enquiry is unresolved without specialist advice. The two claims interact procedurally.
When to call an advisor before borrowing
Always. R&D enquiries are technical and the outcome materially affects the cashflow timing assumption. Engage the original R&D claim adviser plus a specialist tax counsel if the original adviser was inexperienced. Any commercial finance against the expected refund should be sized against the realistic (not the optimistic) enquiry outcome.
Related
- · All HMRC pressure scenarios
- · Our post-decline routing (if mainstream lenders have declined)
- · After a decline: alternative lenders
Editorial only. We are not an FCA-authorised adviser or licensed insolvency practitioner. For active enforcement action, contact a licensed insolvency practitioner directly.