Tax

R&D Tax Credits: A Complete Guide for UK Businesses

Many businesses miss out on R&D tax relief. Learn what to prepare before speaking to a specialist adviser.

Published 5 October 2024Updated 13 June 20266 min read

R&D tax relief claims require both financial evidence and a clear technical explanation. Businesses should prepare project detail before engaging a specialist so the adviser can assess eligibility properly.

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FindAccountants.uk editorial team

Directory editors who maintain accountant-comparison guidance using official sources, service-page context, and FindAccountants.uk profile data.

Reviewed

Last checked 13 June 2026.

Official source links are provided where rules, thresholds, or compliance duties may change.

How this guide is reviewed

FindAccountants.uk guides are reviewed for practical accountant-comparison usefulness, source quality, internal service-page alignment, and clear warnings where tax rules or thresholds may change. Where a guide discusses HMRC, tax, VAT, payroll, or company compliance, it links to official GOV.UK or HMRC resources so readers can verify current rules before making decisions.

Focus on uncertainty and advancement

A strong claim explains what technical uncertainty the team faced, why the answer was not obvious, and what work was done to resolve it. Routine product development is not enough on its own.

The technical narrative should be written in plain language but supported by project evidence.

Prepare the cost evidence

Specialists will usually ask about staff time, subcontractors, software, consumables, and other project costs. The quality of the cost allocation matters, especially if people worked on both qualifying and non-qualifying activity.

Choose a specialist carefully

Ask how the adviser handles eligibility, documentation, HMRC questions, and fee structure. A good adviser should challenge weak claims rather than simply maximise the number.

What to prepare before speaking to an accountant

- Project descriptions
- Technical uncertainty notes
- Staff time estimates
- Cost records
- Evidence of testing or development work

Official guidance to check

Rules and thresholds can change. Use these official sources alongside accountant advice before making tax or compliance decisions.

Check if you can claim R&D tax reliefHMRC guidance on qualifying projects, Corporation Tax, and R&D relief claims.Submit R&D additional informationOfficial guidance on the additional information form required for many R&D claims.

Related accountant resources

Compare R&D tax accountantsFind firms with experience in R&D tax relief claims and project documentation.Find corporation tax accountantsBrowse firms that support limited company tax compliance and planning.Request specialist accountant quotesExplain your project and get introduced to suitable accountancy firms.Read the accountant selection guideCheck what to ask before hiring a specialist adviser.