TXT In plain English
Company description
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED is a UK company whose Companies House status is “Active” and whose registered company type is “Private Limited Company”. Incorporated on 7 October 1999; registered for 27 years; registered office reported in WARRINGTON. Its primary declared activity is 71122 · Engineering related scientific and technical consulting activities, with 1 additional SIC activity reported.
This BritDB profile also contains linked public records: 111 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
- UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED
- Company number
- 03857752
- 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
30 September 2025Next accounts due
30 June 2027Last statement made up to
7 October 2025Next statement due
21 October 2026BritDB does not infer overdue status when the source does not state it.
03 Workforce reporting
Gender pay gap
- Median bonus gap
- 0.0%
- Mean bonus gap
- 21.1%
- Women receiving bonus
- 85.4%
- Men receiving bonus
- 87.8%
- Women in top quartile
- 26.0%
- Women in upper middle quartile
- 29.3%
- Women in lower middle quartile
- 33.3%
- Women in lower quartile
- 41.5%
Earlier reporting years (8)
- 1000 to 499911.7% median hourly gap
- 1000 to 49998.4% median hourly gap
- 1000 to 499916.0% median hourly gap
- 1000 to 499914.4% median hourly gap
- 1000 to 499916.9% median hourly gap
- 500 to 99916.8% median hourly gap
- 500 to 99916.8% median hourly gap
- 500 to 99918.0% 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
- 28 April 2026
- Shortest standard term
- 0 days
- Longest standard term
- 61 days
- E-invoicing offered
- No
- Supply-chain finance
- Not offered
- Payment codes
- UKNNL follows the Prompt Payers Code of Practice
- Construction retentions
- No qualifying construction contracts
Complete reported payment fields
- Policy regime
- Regime-3
- Financial period started
- 1 October 2025
- Qualifying contracts
- Yes
- Payments made
- Yes
- Invoice value paid within 30 days
- £35,298,828
- Invoice value paid in 31–60 days
- £7,039,887
- Invoice value paid after 60 days
- £173
- Invoice value paid outside agreed terms
- £7,040,060
- Invoices paid in 31–60 days
- 7.0%
- Invoices unpaid due to dispute
- 0.0%
- Maximum contractual payment period
- 61 days
- Supplier-list charging policy
- No
- Supplier-list charges made
- No
Maximum contractual payment information
N/A
Reported terms and dispute process
- Standard payment terms
UKNNL uses a Procurement card to settle a significant proportion (42.52%) of its supply chain purchases immediately. Where credit terms are operated our standard practice is to pay undisputed valid invoices within 30 days of receipt. However, variations to these terms do exist based on agreements with certain suppliers which were in place prior to UKNNL becoming a Contracting Authority on 1 April 2017.
Supplier payments are processed weekly. - Dispute resolution process
The company is committed to dealing with its suppliers in a fair, honest and professional manner while seeking best value for the business. We seek to resolve queries as quickly as possible to everyone's satisfaction prior to payment falling due. In the event that a dispute cannot be resolved by our Accounts Payable team, it would be escalated in the first instance to the relevant Head of Department to seek resolution.
Earlier payment reports (11 shown)
- 10.0 average days to pay1.0% outside terms
- 8.0 average days to pay2.0% outside terms
- 8.0 average days to pay3.0% outside terms
- 9.0 average days to pay3.0% outside terms
- 9.0 average days to pay2.0% outside terms
- 7.0 average days to pay2.0% outside terms
- 7.0 average days to pay2.0% outside terms
- 7.0 average days to pay2.0% outside terms
- 8.0 average days to pay4.0% outside terms
- 7.0 average days to pay3.0% outside terms
- 8.0 average days to pay5.0% 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
- UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED
- Group submission
- No
- Statement period
- 1 April 2024 – 31 March 2025
- Approved
- 25 July 2025
- Sectors
- Other
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
- 12 August 2025
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
United Kingdom National Nuclear Laboratory Limited
Registration ZA106149
- Registered from
- 16 March 2015
- Current end date
- 15 March 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 Public procurement
Contracts Finder awards
Engage 2 - Hosting Generation IV International Forum Autumn 2024 Meeting
DESNZ · ocds-b5fd17-fdb9a405-7d88-4f41-9e50-e7464abb7e0f
- Supplier named in award
- NATIONAL NUCLEAR LABORATORY LIMITED
- Award value
- £150,000
- Contract period
- 2 September 2024 – 31 March 2025
- Published
- 24 October 2024
- Procedure
- Single tender action (below threshold)
- Main CPV
- 73210000
- Source release ID
- ocds-b5fd17-fdb9a405-7d88-4f41-9e50-e7464abb7e0f-2024-10-24T09:55:53+01:00
Engage 2: International Engagement Research
DESNZ · ocds-b5fd17-c2906030-93dd-4d16-8ee1-d6fcb13f8dee
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £141,012
- Contract period
- 19 August 2024 – 31 March 2025
- Published
- 4 October 2024
- Procedure
- Single tender action (below threshold)
- Main CPV
- 73110000
- Source release ID
- ocds-b5fd17-c2906030-93dd-4d16-8ee1-d6fcb13f8dee-2024-10-04T16:38:56+01:00
Pelleting Work for ESA
NATIONAL NUCLEAR LABORATORY LIMITED · ocds-b5fd17-26a92b79-d4eb-4089-b6c7-dcf438a78aa9
- Supplier named in award
- University of Manchester
- Award value
- £64,529.53
- Contract period
- 1 May 2024 – 30 October 2024
- Published
- 12 August 2024
- Procedure
- Other - Direct Award
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-26a92b79-d4eb-4089-b6c7-dcf438a78aa9-2024-08-12T09:20:32+01:00
Cold Press & Sinter Phase 2
NUCLEAR DECOMMISSIONING AUTHORITY · ocds-b5fd17-0d40a03e-05e8-4e89-b45d-f4900f625518
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £311,125.05
- Contract period
- 7 November 2022 – 31 December 2023
- Published
- 9 November 2022
- Procedure
- Other - Direct Award
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-0d40a03e-05e8-4e89-b45d-f4900f625518-2022-11-09T13:43:44Z
The Provision of a compact PU Active SEM
NUCLEAR DECOMMISSIONING AUTHORITY · ocds-b5fd17-3b4d657d-5bf5-49a1-ac5b-3648335ed0d3
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £399,534.16
- Contract period
- 7 November 2022 – 31 March 2023
- Published
- 9 November 2022
- Procedure
- Other - Direct award
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-3b4d657d-5bf5-49a1-ac5b-3648335ed0d3-2022-11-09T13:30:45Z
Nuclear Protection - Development of the UK Nuclear Forensic Library 2
Department for Business, Energy & Industrial Strategy · ocds-b5fd17-a793dc6d-1387-469a-948a-e695de6c6f5b
- Supplier named in award
- National Nuclear Laboratory Limited
- Award value
- £600,000
- Contract period
- 1 August 2022 – 31 March 2025
- Published
- 19 May 2023
- Procedure
- Other - Direct Award
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-a793dc6d-1387-469a-948a-e695de6c6f5b-2023-05-19T10:05:35+01:00
SBRI Low Carbon Hydrogen Supply 2 Competition Stream 1 Phase 1
Business Energy and Industrial Strategy · ocds-b5fd17-8dd5317d-5fe1-44db-a942-19adaa21ba80
- Supplier named in award
- National Nuclear Laboratory Limited
- Award value
- £242,619.27
- Contract period
- 10 January 2022 – 10 October 2022
- Published
- 13 May 2022
- Procedure
- Other - SBRI
- Main CPV
- 24111600
- Source release ID
- ocds-b5fd17-8dd5317d-5fe1-44db-a942-19adaa21ba80-2022-05-13T14:42:22+01:00
Sellafield Transmutation of Elements in an Accelerator) STELLAR
Business Energy and Industrial Strategy · ocds-b5fd17-98e686da-2bce-49be-9543-b81cecec8ebc
- Supplier named in award
- NATIONAL NUCLEAR LABORATORY LIMITED
- Award value
- £883,000
- Contract period
- 11 October 2021 – 31 March 2022
- Published
- 26 October 2021
- Procedure
- Negotiated procedure without prior publication (above threshold)
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-98e686da-2bce-49be-9543-b81cecec8ebc-2021-10-26T17:06:40+01:00
Virtual Centre for the Application of Nuclear Systems VULCANS
Business Energy and Industrial Strategy · ocds-b5fd17-846abde3-a8f3-47c3-8ec6-3371cda5d179
- Supplier named in award
- NATIONAL NUCLEAR LABORATORY LIMITED
- Award value
- £883,000
- Contract period
- 11 October 2021 – 31 March 2022
- Published
- 26 October 2021
- Procedure
- Negotiated procedure without prior publication (above threshold)
- Main CPV
- 35113200
- Source release ID
- ocds-b5fd17-846abde3-a8f3-47c3-8ec6-3371cda5d179-2021-10-26T16:52:51+01:00
Development of the UK Nuclear Forensic Library
Business Energy and Industrial Strategy · ocds-b5fd17-c6b2ebe2-c216-4456-a799-5cff825982bb
- Supplier named in award
- NATIONAL NUCLEAR LABORATORY LIMITED
- Award value
- £200,000
- Contract period
- 4 October 2021 – 31 March 2022
- Published
- 22 October 2021
- Procedure
- Negotiated procedure without prior publication (above threshold)
- Main CPV
- 39155100
- Source release ID
- ocds-b5fd17-c6b2ebe2-c216-4456-a799-5cff825982bb-2021-10-22T12:08:55+01:00
PROVISION OF A PILOT FOR ADVANCED NUCLEAR SKILLS AND INNOVATION RESEARCH CAMPUS
Business Energy and Industrial Strategy · ocds-b5fd17-49e67d7c-9632-4eb7-aea9-248cb4f18b65
- Supplier named in award
- NATIONAL NUCLEAR LABORATORY LIMITED
- Award value
- £308,000
- Contract period
- 29 July 2021 – 31 March 2022
- Published
- 15 September 2021
- Procedure
- Single tender action (below threshold)
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-49e67d7c-9632-4eb7-aea9-248cb4f18b65-2021-09-15T14:26:09+01:00
PhD Supervision
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-606ea950-7d51-4294-9925-86f47b8e9c17
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £28,021
- Contract period
- 5 March 2021 – 31 March 2025
- Published
- 6 March 2021
- Procedure
- Single tender action (below threshold)
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-606ea950-7d51-4294-9925-86f47b8e9c17-2021-03-06T21:24:20Z
Anendment of Polymer Encapsulants Report
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-d5364fe1-4970-4adf-b000-d57a9cb34912
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £15,000
- Contract period
- 21 October 2019 – 31 March 2020
- Published
- 22 October 2019
- Procedure
- Single tender action (below threshold)
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-d5364fe1-4970-4adf-b000-d57a9cb34912-2019-10-22T12:07:06+01:00
Costs associated with activites in Compensation Event
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-f1dcfee4-906d-4468-8821-c176698d15f0
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £162,445
- Contract period
- 10 October 2019 – 31 March 2020
- Published
- 14 October 2019
- Procedure
- Call-off from a framework agreement
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-f1dcfee4-906d-4468-8821-c176698d15f0-2019-10-14T13:29:17+01:00
WAGR Spent Fuel Leaching (Phase 1b)
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-ca98abbf-bf4f-4f20-8e6d-d9ab570fbcf7
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £150,488
- Contract period
- 16 April 2019 – 14 August 2019
- Published
- 17 April 2019
- Procedure
- Call-off from a framework agreement
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-ca98abbf-bf4f-4f20-8e6d-d9ab570fbcf7-2019-04-17T11:23:01+01:00
NEA Membership Subscription
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-a409a8ac-8bb6-4af8-a112-44125044dbe0
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £150,000
- Contract period
- 8 March 2019 – 31 March 2022
- Published
- 23 April 2019
- Procedure
- Other - Subscription
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-a409a8ac-8bb6-4af8-a112-44125044dbe0-2019-04-23T14:26:34+01:00
WAGR Spent Fuel Leaching Event EV32592107
RADIOACTIVE WASTE MANAGEMENT LIMITED · ocds-b5fd17-402b2643-17c9-48de-ac9a-92348b015d51
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £275,960
- Contract period
- 29 October 2018 – 31 March 2019
- Published
- 7 January 2019
- Procedure
- Call-off from a framework agreement
- Main CPV
- 73000000
- Source release ID
- ocds-b5fd17-402b2643-17c9-48de-ac9a-92348b015d51-2019-01-07T10:01:45Z
National Waste Quality Checking Service for Radioactive Waste
Defra Network eTendering Portal · ocds-b5fd17-479504af-a558-4ab0-8e4e-09ce5ec7bb81
- Supplier named in award
- National Nuclear Laboratory
- Award value
- £1,000,000
- Contract period
- 10 September 2018 – 9 September 2022
- Published
- 18 December 2018
- Procedure
- Competitive procedure with negotiation (above threshold)
- Main CPV
- 71600000
- Source release ID
- ocds-b5fd17-479504af-a558-4ab0-8e4e-09ce5ec7bb81-2018-12-18T11:35:42Z
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.
08 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.
09 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.
10 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.
11 Public procurement
Find a Tender links
Nuclear Innovation and Research Advisory Board (NIRAB)
Department for Energy Security & Net Zero · updated 1 July 2026
- Tender value
- Not supplied
- Awards
- 2
Nuclear Safeguards Programme
Department for Energy Security & Net Zero · updated 1 June 2026
- Tender value
- £19,500,000
- Awards
- 1
ThermoChimie Phase 4 Framework
Nuclear Waste Services Limited · updated 21 May 2026
- Tender value
- £2,500,000
- Awards
- 4
Provision of the Nuclear Innovation and Research Office (NIRO)
Department for Energy Security & Net Zero · updated 1 September 2025
- Tender value
- Not supplied
- Awards
- 1
RNU Specialist Response
Home Office · updated 19 May 2025
- Tender value
- Not supplied
- Awards
- 1
Consolidated Equipment Services/ Repair Contracts
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 17 September 2026
- Tender value
- Not supplied
- Awards
- 0
Advisory and Consultancy Services to support WIT 2 Coding.
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 7 September 2026
- Tender value
- Not supplied
- Awards
- 1
Institute for Customer Service Membership
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 25 August 2026
- Tender value
- Not supplied
- Awards
- 1
Preliminary Design Call-off Contract
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 20 August 2026
- Tender value
- Not supplied
- Awards
- 1
Strategic Design Partner to Support Deconversion - Framework Agreement
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 20 August 2026
- Tender value
- £3,500,000
- Awards
- 3
Provision of ANSWERS/FISPIN Nuclear Software Codes
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 19 August 2026
- Tender value
- Not supplied
- Awards
- 1
Open Framework for Nuclear Technical Services
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 18 August 2026
- Tender value
- £10,000,000
- Awards
- 10
ATROPOS project
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 4 August 2026
- Tender value
- Not supplied
- Awards
- 0
UKNNL Strategic Plan
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 3 August 2026
- Tender value
- Not supplied
- Awards
- 1
Scientific Journal Access
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 29 July 2026
- Tender value
- Not supplied
- Awards
- 1
Supply of Hoppers, Screwfeeders, Vibratory Feeders and Rotary Barrels
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 29 July 2026
- Tender value
- £150,000
- Awards
- 0
Managed Security Operations Centre (SOC) and Incident Response Services Agreement
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 23 July 2026
- Tender value
- £2,500,000
- Awards
- 0
VP Chemical Testing Phase III
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 21 July 2026
- Tender value
- Not supplied
- Awards
- 1
NNLC746 - Nuclear Advanced Computing & Innovation Partnership (NACIP)
United Kingdom National Nuclear Laboratory · updated 2 July 2026
- Tender value
- £500,000
- Awards
- 0
Provision of Land Quality & End Estates Technical Support Services.
UNITED KINGDOM NATIONAL NUCLEAR LABORATORY LIMITED · updated 12 June 2026
- Tender value
- Not supplied
- Awards
- 1
Showing the first 20 of 93 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.
12 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.
13 Nature of business
Standard Industrial Classification
Technical testing and analysis
14 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
93 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.
15 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
- Company name
Previous name: NATIONAL NUCLEAR LABORATORY LIMITED
- Company name
Previous name: NEXIA SOLUTIONS LIMITED
- Incorporation
Company incorporated
16 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.
Historic awards linked by exact source-supplied GB-COH company identifier.
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.