TXT In plain English
Company description
DIAMOND LIGHT SOURCE LIMITED is a UK company whose Companies House status is “Active” and whose registered company type is “Private Limited Company”. Incorporated on 18 February 2002; registered for 24 years; registered office reported in DIDCOT, OXFORDSHIRE, ENGLAND. Its primary declared activity is 72190 · Other research and experimental development on natural sciences and engineering.
This BritDB profile also contains linked public records: 2 PSC records, 104 procurement records. This description is assembled from public data, is not a reliability assessment, and should be checked against the cited sources before a legally significant decision.
Web facts are never added from a name match alone. Internet enrichment requires the exact Companies House ID in Wikidata, and ambiguous results are excluded.
01 Company overview
Identity and registration
- Official name
- DIAMOND LIGHT SOURCE LIMITED
- Company number
- 04375679
- Company type
- Private Limited Company
- Status
- Active
- Country of origin
- United Kingdom
- Dissolution date
- Not supplied
- Accounts category
- FULL
- Mortgage charges
- 0 total · 0 outstanding · 0 satisfied
- Limited partnership members
- 0 general · 0 limited
A registered office is not necessarily a trading location. The address is reproduced from the Companies House bulk record and should be interpreted in that legal context.
02 Filing dates
Accounts and statements
Last accounts made up to
31 March 2026Next accounts due
31 December 2027Last statement made up to
1 May 2026Next statement due
15 May 2027BritDB does not infer overdue status when the source does not state it.
03 Workforce reporting
Gender pay gap
- Median bonus gap
- -23.1%
- Mean bonus gap
- -21.0%
- Women receiving bonus
- 86.7%
- Men receiving bonus
- 88.0%
- Women in top quartile
- 17.0%
- Women in upper middle quartile
- 22.0%
- Women in lower middle quartile
- 25.0%
- Women in lower quartile
- 29.0%
Earlier reporting years (8)
- 500 to 99913.7% median hourly gap
- 500 to 9996.7% median hourly gap
- 500 to 9997.2% median hourly gap
- 500 to 9995.7% median hourly gap
- 500 to 9997.7% median hourly gap
- 500 to 9992.9% median hourly gap
- 500 to 9995.8% median hourly gap
- 500 to 9996.4% median hourly gap
Positive gaps mean men were paid more; negative gaps mean women were paid more. These figures are employer-reported and describe the workforce distribution, not equal pay for the same job. The company link uses the exact Companies House number supplied by the service.
04 Supplier payments
Payment practices and performance
- Reporting period
- 1 October 2025 – 31 March 2026
- Filed
- 23 April 2026
- Shortest standard term
- 30 days
- Longest standard term
- Not supplied
- E-invoicing offered
- No
- Supply-chain finance
- Offered
- Payment codes
- No
- Construction retentions
- Reported as used
Complete reported payment fields
- Policy regime
- Regime-3
- Financial period started
- 1 April 2025
- Qualifying contracts
- Yes
- Payments made
- Yes
- Invoice value paid within 30 days
- £59,588,553
- Invoice value paid in 31–60 days
- £8,964,970
- Invoice value paid after 60 days
- £2,833,444
- Invoice value paid outside agreed terms
- £659,916
- Invoices paid in 31–60 days
- 11.0%
- Invoices unpaid due to dispute
- 15.0%
- Maximum contractual payment period
- 30 days
- Supplier-list charging policy
- No
- Supplier-list charges made
- No
Retention release
Half of the retention is released on Completion. The other half is released at the end of the defects period.
Retention release stages
Half of the retention is released on Completion. The other half is released at the end of the defects period.
- Retention in all contracts
- Yes
- Retention in standard terms
- No
- Retention threshold
- Not supplied
- Standard retention rate
- Not supplied
- Retention compared with client
- 0.0%
- Retention compared with payments
- 6.0%
Reported terms and dispute process
- Standard payment terms
Diamond Light Source Limited's standard payment terms are 30 days from the date of invoice receipt.
There were no changes to the standard payment terms in the reporting period. - Dispute resolution process
For payment related queries, please contact Accounts payable on the email below, copying in the requestor of the purchase order, or call the Accounts payable department: dlsaccountspayable@diamond.ac.uk.
Purchase order queries - the Supplier should contact the requestor of the purchase order or procurement.
Earlier payment reports (11 shown)
- 28.0 average days to pay11.0% outside terms
- 27.0 average days to pay11.0% outside terms
- 27.0 average days to pay11.0% outside terms
- 28.0 average days to pay12.0% outside terms
- 30.0 average days to pay26.0% outside terms
- 28.0 average days to pay13.0% outside terms
- 30.0 average days to pay15.0% outside terms
- 29.0 average days to pay16.0% outside terms
- 29.0 average days to pay15.0% outside terms
- 30.0 average days to pay19.0% outside terms
- 32.0 average days to pay22.0% outside terms
This is a company-submitted statutory disclosure, not a credit rating. BritDB preserves the reporting period and links the report only through the Companies House number supplied by the official service. Percentages describe payments made during that period and may change in later reports.
05 Supply-chain transparency
Modern slavery statement
- Organisation
- DIAMOND LIGHT SOURCE LIMITED
- Group submission
- No
- Statement period
- 1 April 2025 – 31 March 2026
- Approved
- 1 July 2026
- Sectors
- Charitable / not-for-profit activities
Organisation structure
Covered in the statement
Policies
Covered in the statement
Risk assessment
Covered in the statement
Due diligence
Covered in the statement
Training
Covered in the statement
Goals and KPIs
Covered in the statement
Full statement information supplied to the registry
- Reported turnover band
- £100 million to £500 million
- Years producing statements
- More than 5 years
- ILO indicators included
- Not answered
- Registry record updated
- 24 August 2026
Policies described
Freedom of workers to terminate employment Freedom of movement Freedom of association Prohibits any threat of violence, harassment and intimidation Prohibits the use of worker-paid recruitment fees Prohibits compulsory overtime Prohibits child labour Prohibits discrimination Prohibits confiscation of workers' original identification documents Provides access to remedy, compensation and justice for victims of modern slavery
Training described
Your whole organisation
A registry entry records what the organisation declared in its statement. It is not an independent audit. Group statements can cover several companies; BritDB preserves each exact source-supplied company-number link and excludes approver names and email addresses.
06 Data protection
ICO fee-payer registration
Diamond Light Source Limited
Registration Z6891625
- Registered from
- 26 June 2002
- Current end date
- 25 June 2027
This is a candidate association, not an official Companies House link. The ICO file supplies no company number. The organisation name and postcode uniquely matched this company in the current snapshot. BritDB excludes all DPO contact fields and does not publish unmatched personal entries.
07 Environmental regulation
Environment Agency records
Diamond Light Source Limited
QB3391DZ · OX11 0DE
- Permit or record holder
- Diamond Light Source Limited
- Record date
- 27 September 2021
- Local authority
- Not supplied
- Regulated site or public record address
- Diamond House, Harwell Science & Innovation Campus, Didcot, OX11 0DE
- Activity
- Keeping & Use of Radioactive Materials and Disposal of Radioactive Waste
- Grid reference
- Site S264.
- Easting
- 447755.000
- Northing
- 186355.000
- All populated source fields
- Permit Number: QB3391DZ; Permit Holder Name: Diamond Light Source Limited; Approved Date: 2021-09-27; Permit Type: Keeping & Use of Radioactive Materials and Disposal of Radioactive Waste; Site Address: Diamond House, Harwell Science & Innovation Campus, Didcot, OX11 0DE; Site Postcode: OX11 0DE; Site Reference: Site S264.; Easting: 447755; Northing: 186355
These are candidate company associations. The public-register downloads do not supply Companies House numbers. BritDB requires one unique exact holder-name and postcode match; the regulated site may differ from the registered office, so verify the record at source.
08 Public procurement
Contracts Finder awards
GSS24834 - Project Management Fees
UK SHARED BUSINESS SERVICES LIMITED · ocds-b5fd17-15604509-8ad7-45ac-8c4a-57447470e02d
- Supplier named in award
- DIAMOND LIGHT SOURCE LIMITED
- Award value
- £24,000
- Contract period
- 22 November 2024 – 31 January 2025
- Published
- 26 November 2024
- Procedure
- Competitive quotation (below threshold)
- Main CPV
- 72224000
- Source release ID
- ocds-b5fd17-15604509-8ad7-45ac-8c4a-57447470e02d-2024-11-26T09:10:34Z
Costs for IAM Project Management Contractor
UK SHARED BUSINESS SERVICES LIMITED · ocds-b5fd17-080032b4-c6ea-479d-88dd-8b3dae36a498
- Supplier named in award
- DIAMOND LIGHT SOURCE LIMITED
- Award value
- £24,000
- Contract period
- 22 November 2024 – 31 December 2024
- Published
- 2 December 2024
- Procedure
- Competitive quotation (below threshold)
- Main CPV
- 72224000
- Source release ID
- ocds-b5fd17-080032b4-c6ea-479d-88dd-8b3dae36a498-2024-12-02T10:48:17Z
The supplier link is exact, but the award remains buyer-published procurement data. BritDB requires the GB-COH identifier supplied in the Contracts Finder OCDS release and does not infer suppliers from similar names.
09 Ownership and control
People with significant control
No individual or entity with signficant control
- Notified
- 26 May 2017
A PSC has been contacted but has not responded
- Notified
- 18 February 2017
- Ceased
- 7 March 2017
PSC records are company-filed public-register information. When the exact same displayed individual name occurs at multiple companies, BritDB offers a non-indexed cross-reference page. It is a name match only, not proof that the records describe the same person. Service addresses and partial dates of birth are deliberately omitted.
10 Charity register
Charity Commission links
No exact company-number link in this snapshot
The Charity Commission extract did not explicitly associate this Companies House number with a charity. BritDB does not use a name-only match to fill the gap.
This company-level check covers the Charity Commission for England and Wales. Links are accepted only when the official extract supplies this exact company registration number. Scottish charities now have separate OSCR profiles, but OSCR’s bulk fields do not provide a Companies House number, so BritDB does not infer a company link.
11 Northern Ireland charity register
CCNI exact company links
No unambiguous company-number link found
The CCNI source number did not resolve uniquely to this Companies House record. BritDB did not use a name or address match.
CCNI publishes company numbers without a jurisdiction prefix. BritDB links only when the plausible padded UK and NI candidates resolve to exactly one Companies House company.
12 Sanctions screening
UK Sanctions List
No exact business-registration-number link found
The imported UK Sanctions List did not supply this Companies House number as a UK-linked business identifier. BritDB did not attempt a name-only match.
No exact link is not sanctions clearance. UK restrictions can apply through ownership or control even where an entity is not separately named. Always use the current official list and obtain appropriate advice for a legally significant decision.
13 Public procurement
Find a Tender links
9005401 - Supply of K14 SWIFT Beamline KB Mirror System
DIAMOND LIGHT SOURCE LIMITED · updated 21 September 2026
- Tender value
- £250,000
- Awards
- 1
DLSITT1071 - Supply of Arc Vessel Support Components for D-II
DIAMOND LIGHT SOURCE LIMITED · updated 14 September 2026
- Tender value
- £900,000
- Awards
- 1
DLSITT1102 - B22 Multiple InfraRed Mirror System for Diamond Light Source
DIAMOND LIGHT SOURCE LIMITED · updated 2 September 2026
- Tender value
- £380,000
- Awards
- 1
DLSITT1105 - New Diamond Website
DIAMOND LIGHT SOURCE LIMITED · updated 26 August 2026
- Tender value
- £90,000
- Awards
- 0
DLSITT1098 - Diamond-II Multipole Wiggler for K14
DIAMOND LIGHT SOURCE LIMITED · updated 19 August 2026
- Tender value
- £180,000
- Awards
- 0
DLSITT1104 - Supply of I14 Beamline M1 and M2 Mirror Systems for Diamond Light Source
DIAMOND LIGHT SOURCE LIMITED · updated 29 July 2026
- Tender value
- £600,000
- Awards
- 0
DLSITT1100 - Supply of APPLE-II Undulator for Beamline K07 for Diamond Light Source
DIAMOND LIGHT SOURCE LIMITED · updated 20 July 2026
- Tender value
- £800,000
- Awards
- 1
9005026 - Supply of APPLE-II Undulator for Beamline K07
DIAMOND LIGHT SOURCE LIMITED · updated 17 July 2026
- Tender value
- Not supplied
- Awards
- 1
9004476 - Supply of B23 Mirror System for Diamond Light Source
DIAMOND LIGHT SOURCE LIMITED · updated 26 May 2026
- Tender value
- £500,000
- Awards
- 1
DLSITT1065 - Supply of a Canted 3-Pole Wiggler for Diamond-II
DIAMOND LIGHT SOURCE LIMITED · updated 12 May 2026
- Tender value
- Not supplied
- Awards
- 1
9004199 - Supply of Booster Kicker Magnets for Diamond-II
DIAMOND LIGHT SOURCE LIMITED · updated 8 April 2026
- Tender value
- £1,200,000
- Awards
- 1
9004200 - Supply of M1 and M2 Collimating Mirror System for I20
DIAMOND LIGHT SOURCE LIMITED · updated 7 April 2026
- Tender value
- £500,000
- Awards
- 1
9004214 - Supply of I13-2 Imaging Beamline Double Multilayer Monochromator System
DIAMOND LIGHT SOURCE LIMITED · updated 7 April 2026
- Tender value
- £500,000
- Awards
- 1
9004143 - Supply of Front End for K14
DIAMOND LIGHT SOURCE LIMITED · updated 7 April 2026
- Tender value
- £450,000
- Awards
- 1
9003990 - Supply of Mechanical Equipment for the D-II Magnets
DIAMOND LIGHT SOURCE LIMITED · updated 19 March 2026
- Tender value
- £750,000
- Awards
- 1
9003706 - Supply of Thin Septum Magnets
DIAMOND LIGHT SOURCE LIMITED · updated 18 March 2026
- Tender value
- £780,000
- Awards
- 1
9004002 - Supply of K14 SWIFT Beamline HRM Mirror Systems
DIAMOND LIGHT SOURCE LIMITED · updated 18 March 2026
- Tender value
- £130,000
- Awards
- 1
9003984 - Supply of the APPLE-II Undulators for I06 and I10
DIAMOND LIGHT SOURCE LIMITED · updated 17 March 2026
- Tender value
- £2,000,000
- Awards
- 1
9003983 - Supply of the APPLE-II Undulator for I08
DIAMOND LIGHT SOURCE LIMITED · updated 17 March 2026
- Tender value
- £1,500,000
- Awards
- 1
DLSITT1065 - Supply of a Canted 3-Pole Wiggler for Diamond-II
DIAMOND LIGHT SOURCE LIMITED · updated 13 March 2026
- Tender value
- £200,000
- Awards
- 0
Showing the first 20 of 102 linked procurement processes.
These links use only the GB-COH identifier supplied in the procurement record. A company may have other public-sector work that is absent, older, below publication thresholds or published without a Companies House identifier.
14 Environmental register
Environment Agency waste registrations
No exact company-number registration linked
The licensed Environment Agency subset did not contain this exact Companies House number. BritDB did not attempt a name-only match.
This is a privacy-reduced, exact-company subset. The full official register also includes sole traders and applicants without a matching Companies House number. Check the current Environment Agency register before relying on registration status.
15 Nature of business
Standard Industrial Classification
16 Connected public record
Checks beyond the company register
Charity Commission
0 exact company-number links.
Northern Ireland charities
0 unambiguous company-number links.
Public contracts
102 procurement processes linked by exact GB-COH identifier.
Waste register
0 exact company-number registrations.
Corporate notices
The Gazette is not yet connected.
UK Sanctions List
No exact business-registration-number link in this report.
A checked source with no exact link is not a clean bill of health. Unchecked sources remain unknown, while sanctions may also apply through ownership or control of a listed person or entity.
17 Record timeline
Dates in the bulk record
- Confirmation statement
Latest confirmation statement made up to this date
- Accounts
Latest accounts made up to this date
- Incorporation
Company incorporated
18 Provenance
Sources for this profile
Identity, address, status, dates, SIC, previous names and mortgage totals.
Annual employer reports linked by the exact source-supplied Companies House number.
Statutory supplier-payment reports linked by the exact source-supplied Companies House number.
Annual statement summaries linked by exact source company number.
Privacy-reduced candidate associations based on a unique exact name-and-postcode match.
Candidate permit and enforcement associations based on a unique exact holder-name and postcode match.
Historic awards linked by exact source-supplied GB-COH company identifier.
Current and ceased significant-control records joined by exact company number.
Daily England and Wales extract matched only by the official company registration number.
Daily CCNI export with company links only where the source number resolves unambiguously.
Complete FCDO list checked by exact UK-linked business registration number.
Procurement parties checked only through exact GB-COH identifiers.
Licensed subset linked only by exact Companies House number.
Financial regulation and licences.
Companies House, Charity Commission, OSCR and UK Sanctions List information is public-register data. BritDB reproduces and organises it with source-specific limits; official external links are kept on the dedicated source pages.