CIRD98900 - R&D tax relief: legislative structure and time line: time line for changes
Source: gov.uk (2025-11-21)


Chronological list of changes

With two schemes in place, which interact with each other, and with amendments in subsequent Finance Acts, the time from which various changes apply can be tricky to identify. To make this process easier we have listed in time order the various changes. This is only intended as an aid to comprehension, and more detailed guidance should be consulted in case of any doubt.

Date

Measure

01/04/00

SME scheme introduced. Minimum spend in an accounting period set at £25,000 per annum. For accounting periods straddling 1 April 2000, it only applied to expenditure on or after that date (CIRD90000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird90000))

28/07/00

DTI Guidelines on the meaning of R&D issued, Current Guidelines are at (CIRD81900 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81900))

01/04/02

Large company scheme introduced. Minimum spend in an accounting period set at £25,000 per annum (CIRD81600 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81600))

01/04/02

SMEs able to claim under the large company scheme for qualifying expenditure where they act as subcontractor to large company and are unable to claim under SME scheme in respect of expenditure incurred on or after this date (CIRD89500 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird89500))

06/04/03

ITEPA changed the definition of staffing costs incurred in accounting periods ending on or after this date to include certain benefits( CIRD83200 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird83200))

09/04/03

For accounting periods beginning on or after this date, SMEs able to claim the relief under the large company scheme where they were barred from a claim under the SME scheme only by reason of being in receipt of subsidised expenditure (CIRD89000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird89000))

09/04/03

For accounting periods beginning on or after this date the minimum spend in an accounting period for large companies set at £10,000 (CIRD81600 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81600))

09/04/03

Expenditure incurred on or after this date by large companies on externally provided workers becomes qualifying expenditure (CIRD84000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird84000))

09/04/03

For expenditure on staffing costs incurred on or after this date there is no 80:20 arrangement under the large company scheme (CIRD83800 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird83800))

27/09/03

For accounting periods beginning on or after this date minimum spend for SMEs set at £10,000 (CIRD81600 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81600))

27/09/03

Expenditure incurred on or after this date by SMEs on externally provided workers became qualifying expenditure (CIRD84000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird84000))

27/09/03

For expenditure on staffing costs incurred on or after this date there is no 80:20 arrangement under the SME scheme (CIRD83800 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird83800))

05/03/04

New guidelines on meaning of R&D issued. Brought into force by SI2004/712 for accounting periods ending on or after 1 April 2004 (CIRD81900 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81900))

01/04/04

ITEPA change to staffing costs reversed (CIRD83250 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird83250))

01/04/04

Consumable items and computer software introduced as, and consumable stores ceased to be, categories of qualifying expenditure for expenditure on or after this date for both the SME and the large company schemes (CIRD82450 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird82450), CIRD82300 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird82300) and CIRD82500 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird82500))

01/01/05

New EU definition of SME to be effective from this date (CIRD91500 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird91500))

01/01/05

Changes to the timing of the relief where expenditure incurred in accounting periods beginning on or after this date is not written off immediately to the profit and loss account (CIRD98500 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird98500))

31/03/06

For accounting periods ending on or after this date the time limit for claims to the enhanced deduction against profits becomes the anniversary of the filing date for the CT return in which the claim is made (CIRD81800 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81800))

01/04/06

Expenditure incurred on or after this date by large companies on subjects of clinical trials became qualifying expenditure (CIRD84400 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird84400))

01/11/06

HMRC sets up specialist R&D units to deal with all claims from companies dealt with outside the LBS (CIRD80300 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird80300))

01/04/08

Clinical trials. New category of expenditure for SME Scheme

01/04/08

Enhanced deduction in Large Scheme increased from 125% to 130% of qualifying expenditure

01/08/08

Enhanced deduction in SME Scheme increased from 150% to 175% of qualifying expenditure

01/08/08

SME’s and Vaccines schemes only. Limits relief to companies that are a going concern when claim is made. (CIRD75100 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird75100) and CIRD81130 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81130))

01/08/08

SME and Vaccines schemes only. Limit of €7.5m on the total amount of aid which can go to any one R&D project.(CIRD81160 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81160))

01/08/08

Definition of SME extended in relation to expenditure incurred on or after this date. (CIRD91900 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird91900))

01/08/08

Vaccines Research Relief. Appropriate deduction decreased from 50% to 40 % of qualifying expenditure.(CIRD75600 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird75600))

01/08/08

Definition of staff costs extended to include overseas NI costs. (CIRD83200 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird83200))

01/08/08

Vaccines Research Relief Change of conditions applying to subcontractor payments to a charity, university or scientific research organisation. (CIRD75525 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird75525))

01/12/08

Change of Status. (CIRD92000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird92000))

26/03/09

CTA 2009.

9/12/09

SME scheme only. Removal of IP condition for accounting periods ending on or after this date. (CIRD81550) (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81550)

01/04/11

Enhanced deduction in SME Scheme increased from 175% to 200% of qualifying expenditure.

01/04/12

Enhanced deduction in SME Scheme increased from 200% to 225% of qualifying expenditure. (CIRD80250 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird80250))

01/04/12

R&D threshold removed in relation to accounting periods ending on or after this date. (CIRD81650 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81650))

01/04/12

Company not a going concern in administration or liquidation in relation to claims made on or after this date. (CIRD81130 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81130))

01/04/12

Removal of restriction of tax credit to PAYE and NIC liabilities in relation to accounting periods ending on or after this date. (CIRD90500 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird90500))

01/04/12

Vaccines Research Relief for SME’s abolished in relation to expenditure incurred on or after this date.

01/04/12

Calculation of qualifying expenditure on externally provided workers relaxed in relation to expenditure incurred on or after this date. (CIRD84000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird84000))

01/04/13

Research and Development Expenditure Credit (RDEC) introduced for expenditure incurred on or after this date.

01/04/14

Payable tax credit rate increased from 11% to 14.5%.

01/04/15

Consumable items: no relief for consumable items that make up part of a product that is sold in the course of a company's ordinary business. Restriction applies to expenditure on consumable items incurred on or after this date.

01/04/15

Enhanced deduction in SME scheme increased from 225% to 230% of qualifying expenditure.

01/04/15

RDEC rate increased from 10% to 11% of qualifying expenditure.

01/08/15

Institutions of higher education (including universities) and charities cannot claim RDEC for expenditure incurred on or after this date.

01/04/16

State aid cao (SME and Vaccines Research Relief schemes only) formula amended to ensure that SMEs continue to receive the same benefit from the calculation in s1114 CTA 2009 as previously.

01/07/16

Finance Act 2016 permits HMRC to collect information from businesses which receive State aid through the tax system, and to share and publish that information. The requirements are set out in Article 9 of Commission Regulation 651/2014 (General Exemption Regulation (GBER)). The new rules apply to all aid notified under either GBER or certain other State aid guidelines.

31/03/17

Vaccines Research Relief abolished in relation to expenditure incurred after this date.

01/01/18

RDEC rate increased from 11% to 12% of qualifying expenditure.

01/04/19

All claims for Research and Development reliefs or Creatives Tax reliefs which form part of an amended return must include a completed CT600 and a Corporation Tax computation. Those items can be included as enclosures to an email. Potential claims without both the completed CT600 and computations will be returned.

01/04/20

RDEC rate increased from 12% to 13% of qualifying expenditure.

01/04/21

CT600L is a supplementary form that must be submitted with a Corporation Tax Return or amendment to a return when an R&D tax credit claim is made.

01/04/21

Introduction of the PAYE Cap. This measure limits the amount of payable R&D tax credit which a SME can claim to £20,000 plus 300% of its total Pay as you Earn (PAYE) and National Insurance Contributions (NICs) liability for the period. There are certain exceptions to the cap. (CIRD90600) (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird90600)

01/04/23

For expenditure on or after 1 April 2023, the Research and Development Expenditure Credit (RDEC) rate increased from 13% to 20%, the SME additional deduction decreased from 130% to 86%, and the small and medium (SME) sized company credit rate decreased from 14.5% to 10% except for SMEs whose R&D intensity is greater than 40%, who continue to receive the 14.5% rate.

01/04/23

For accounting periods starting on or after 1 April 2023 Data licence and Cloud computing services costs can be qualifying expenditure when employed in activities which directly contribute to the resolution of scientific or technological uncertainty.

01/04/23

For accounting periods starting on or after 1 April 2023:

· Some customers will need to submit a Claim Notification form for their R&D claim to be valid. (CIRD81800 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81800))

01/04/23

From 1 April 2023 the DSIT guidelines have been updated to make clear that activities relating to Pure Mathematics now meet the definition of R&D for tax purposes.

01/08/23

For claims made on or after 8 August 2023 for an R&D claim to be valid a customer must submit an Additional Information form CIRD182000 (https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird182000).