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    Claim process

    R&D claim process and deadlines

    A supportable claim brings the technical basis, qualifying expenditure and Corporation Tax submission together for the correct accounting period.

    Reviewed by Richard Canfer-Taylor
    Published and reviewed 15 September 2026

    Key points

    • Confirm the accounting period and claim history first.
    • Some first-time or returning claimants must submit claim notification within the statutory window.
    • An Additional Information Form is generally required before the Company Tax Return is submitted or amended.
    • The normal amendment deadline and any enquiry window must be checked for the specific period.

    Establish the filing route

    Collect the accounting-period dates, Company Tax Return position and details of previous R&D claims. This determines which scheme, notification rules and deadlines require review.

    Prepare technical and cost support

    Identify qualifying projects, capture explanations from competent professionals, calculate qualifying expenditure and reconcile the figures to the accounts. Agree who will complete the Additional Information Form and Corporation Tax entries.

    Treat dates as case-specific

    Do not rely on a generic two-year statement without checking the accounting period, filing history and current guidance. If a deadline may be close, obtain advice promptly.