Reviews and audits by country | Research Credit Integrity Alliance

This page compares how the five countries covered on this site check research and development (R&D) tax claims after they are made. For each country it sets out who carries out the review, how claims are selected, and the general time limit for the authority to reassess. Each cell cites the same source as the matching country page. Published figures on review outcomes, where they exist, are in the notes below; they cover different years and measures, so they are not directly comparable. The page describes the rules only and makes no recommendation.

Country	Who reviews	How claims are selected	General time limit to reassess
United States	The IRS; research credit refund claims are also checked for validity before any review of the merits1	Computer screening against statistical norms, related examinations and other methods; amended returns are screened2	Generally 3 years after the return was filed3
United Kingdom	HMRC, including specialist staff and the R&D Anti-Abuse Unit4	Every claim is risk assessed; a random enquiry program measures error and fraud4	Generally 12 months from the claim to open a check, with discovery assessments possible later4
Ireland	Revenue, which may consult independent experts on the science test56	Risk indicators, plus a relatively small number of randomly selected cases7	Generally four years from the end of the chargeable period in which the return was filed8
Canada	A CRA research and technology advisor for the work and a financial reviewer for the expenditures9	Risk assessment of every claim, or other reasons such as random sampling9	Three or four years from the original notice of assessment, depending on the taxpayer10
Singapore	IRAS, which may seek technical advice and refer cases to its Technical Advisory Panel11	Risk based profiling by complexity and risk to revenue12	Generally four years after the end of the Year of Assessment13

Notes

United States. If a research credit refund claim lacks required information, the IRS allows 45 days to perfect it during a transition period that it says runs through 10 January 2027; otherwise the claim is rejected.1 A refund above $2,000,000, or $5,000,000 for a C corporation, cannot be made until 30 days after a report to the Joint Committee on Taxation.14

United Kingdom. HMRC reported 9,700 compliance checks in 2023 to 2024, or 17 percent of claims received, excluding cases handled by its Large Business teams.4 In its random enquiry program for claims received in 2021 to 2022, HMRC found 49 percent of SME claims examined were compliant.4

Ireland. Revenue examines two main elements of an R&D claim, the science test and the accounting test.5 The taxpayer and any agent on record receive 28 days' notice of a risk review or audit.7 The four year limit does not apply where the return did not contain a full and true disclosure, or where fraud or neglect is suspected.8

Canada. The CRA's service standards are 60 calendar days for claims accepted as filed and 180 calendar days for refundable claims selected for review.15 The CRA's risk assessment criteria were not found in the sources reviewed.

Singapore. An EIS cash payout is paid only after IRAS has assessed and verified the claim, and may be audited afterwards.16 IRAS reported that in 2018, of the SME R&D claims processed, 83 percent were granted full benefits and 6 percent were adjusted; no later figures were found.17

Sources

Internal Revenue Service, Research credit claims (Section 41) on amended returns frequently asked questions, introduction and questions 3 to 7 and 16 (page last reviewed or updated 1 October 2026). https://www.irs.gov/businesses/corporations/research-credit-claims-section-41-on-amended-returns-frequently-asked-questions (accessed 11 October 2026). Back
Internal Revenue Service, IRS audits, sections on selection methods, notification, how audits are conducted and records (page last reviewed or updated 17 February 2026). https://www.irs.gov/businesses/small-businesses-self-employed/irs-audits (accessed 11 October 2026). Back
Office of the Law Revision Counsel, 26 U.S.C. 6501, Limitations on assessment and collection, subsection (a), United States Code 2024 edition published by the Government Publishing Office. https://www.govinfo.gov/content/pkg/USCODE-2024-title26/html/USCODE-2024-title26-subtitleF-chap66-subchapA-sec6501.htm (accessed 11 October 2026). Back
HM Revenue and Customs, Approach to Research and Development tax reliefs 2023 to 2024 (published 30 October 2024), sections 1.2, 2.4 (including "Tailoring the approach", "Compliance check framework" and Table 4) and 2.5, and Annex B, Themes 1 and 5. https://www.gov.uk/government/publications/hmrcs-approach-to-research-and-development-tax-reliefs-2023-to-2024/approach-to-research-and-development-tax-reliefs-2023-to-2024 (accessed 11 October 2026). Back
Revenue Commissioners, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), sections 8, 8.1, 8.2, 8.6.2 and 8.7. https://www.revenue.ie/en/tax-professionals/tdm/income-tax-capital-gains-tax-corporation-tax/part-29/29-02-03.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 29, section 766, subsection (7). https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part29.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Code of Practice for Revenue Compliance Interventions (effective 1 May 2022), sections 1.1, 1.2.2, 1.3, 1.3.1 to 1.3.3, 1.4, 2.10 and 4.11. https://www.revenue.ie/en/tax-professionals/documents/code-of-practice-revenue-compliance-interventions.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 41A, sections 959Z and 959AA. https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part41a.pdf (accessed 11 October 2026). Back
Canada Revenue Agency, The SR&ED Review Process: A Guide for Claimants (April 20, 2026), sections on the purpose of a review, pre-claim approval, selection for review, withdrawal, how the CRA conducts a review, Steps 1 to 3, and Appendix A. https://www.canada.ca/en/revenue-agency/services/scientific-research-experimental-development-tax-incentive-program/technical-review-a-guide-claimants.html (accessed 11 October 2026). Back
Government of Canada, Income Tax Act, RSC 1985, c 1 (5th Supp), subsections 152(3.1) and (4). https://laws-lois.justice.gc.ca/eng/acts/I-3.3/section-152.html (accessed 11 October 2026). Back
Inland Revenue Authority of Singapore, IRAS e-Tax Guide: Research and Development Tax Measures (Eighth Edition, published 30 January 2026), paragraphs 13.1 to 13.6 and footnote 23. https://www.iras.gov.sg/docs/default-source/e-tax/research-and-development-tax-measures-etax-guide_6th-edition.pdf?sfvrsn=1f38a2e8_27 (accessed 11 October 2026). Back
Inland Revenue Authority of Singapore, After Filing Form C-S/ Form C-S (Lite)/ Form C (last updated 29 May 2026), section "Tax Assessment Process". https://www.iras.gov.sg/taxes/corporate-income-tax/form-c-s-form-c-s-(lite)-form-c-filing/after-filing-form-c-s-form-c-s-(lite)-form-c (accessed 11 October 2026). Back
Attorney-General's Chambers, Income Tax Act 1947 (Singapore Statutes Online, current version), section 74(1) and (2). https://sso.agc.gov.sg/Act/ITA1947?ProvIds=pr74- (accessed 11 October 2026). Back
Office of the Law Revision Counsel, 26 U.S.C. 6405, Reports of refunds and credits, subsection (a), United States Code 2024 edition published by the Government Publishing Office. https://www.govinfo.gov/content/pkg/USCODE-2024-title26/html/USCODE-2024-title26-subtitleF-chap65-subchapA-sec6405.htm (accessed 11 October 2026). Back
Canada Revenue Agency, SR&ED Program Service Standards. https://www.canada.ca/en/revenue-agency/services/scientific-research-experimental-development-tax-incentive-program/program-service-standards.html (accessed 11 October 2026). Back
Inland Revenue Authority of Singapore, IRAS e-Tax Guide: Enterprise Innovation Scheme (Third Edition, published 31 August 2026), paragraphs 6.9 and 6.10. https://www.iras.gov.sg/docs/default-source/e-tax/etaxguide_cit_enterprise-innovation-scheme.pdf?sfvrsn=3a36afd3_12 (accessed 11 October 2026). Back
Inland Revenue Authority of Singapore, Research & Development (R&D) Tax Measures (last updated 13 August 2026), sections "What Qualifies for R&D Tax Deductions", "Review Process", "Technical Advisory Panel" and "R&D Assurance Framework" (including FAQs). https://www.iras.gov.sg/taxes/corporate-income-tax/income-deductions-for-companies/business-expenses/research-development-(r-d)-tax-measures (accessed 11 October 2026). Back