TXT In plain English
Company description
MWH TREATMENT LIMITED is a UK company whose Companies House status is “Active” and whose registered company type is “Private Limited Company”. Incorporated on 17 December 1980; registered for 45 years; registered office reported in CHESHIRE, ENGLAND. Its primary declared activity is 42910 · Construction of water projects, with 1 additional SIC activity reported.
This BritDB profile also contains linked public records: 2 PSC records, 2 procurement records, 1 waste registration. 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
- MWH TREATMENT LIMITED
- Company number
- 01535477
- Company type
- Private Limited Company
- Status
- Active
- Country of origin
- United Kingdom
- Dissolution date
- Not supplied
- Accounts category
- FULL
- Mortgage charges
- 10 total · 2 outstanding · 8 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 2025Next accounts due
31 December 2026Last statement made up to
12 August 2026Next statement due
26 August 2027BritDB does not infer overdue status when the source does not state it.
03 Workforce reporting
Gender pay gap
- Median bonus gap
- 76.3%
- Mean bonus gap
- 46.1%
- Women receiving bonus
- 53.1%
- Men receiving bonus
- 54.4%
- Women in top quartile
- 12.8%
- Women in upper middle quartile
- 12.3%
- Women in lower middle quartile
- 25.6%
- Women in lower quartile
- 43.9%
Earlier reporting years (8)
- 500 to 99931.3% median hourly gap
- 500 to 99927.7% median hourly gap
- 500 to 99924.7% median hourly gap
- 250 to 49925.1% median hourly gap
- 250 to 49930.7% median hourly gap
- 250 to 49934.0% median hourly gap
- 500 to 99931.7% median hourly gap
- 500 to 99934.0% 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 January 2026 – 30 June 2026
- Filed
- 29 July 2026
- Shortest standard term
- 1 days
- Longest standard term
- 60 days
- E-invoicing offered
- No
- Supply-chain finance
- Not offered
- Payment codes
- No
- Construction retentions
- Reported as used
Complete reported payment fields
- Policy regime
- Regime-3
- Financial period started
- 1 January 2026
- Qualifying contracts
- Yes
- Payments made
- Yes
- Invoice value paid within 30 days
- £90,272,284
- Invoice value paid in 31–60 days
- £25,607,645
- Invoice value paid after 60 days
- £1,500,048
- Invoice value paid outside agreed terms
- £13,260,548
- Invoices paid in 31–60 days
- 40.0%
- Invoices unpaid due to dispute
- 0.0%
- Maximum contractual payment period
- 60 days
- Supplier-list charging policy
- No
- Supplier-list charges made
- No
Retention circumstances
MWH Treatment Limited typically apply supplier retention clauses where it is imposed on us in the head contract.
Retention parity policy
5% is the most frequently used percentage retention rate in respect of qualifying construction contracts. Where a different percentage is applied this will have been agreed with the supplier before commencement of the contract.
Retention release
MWH Treatment Limited releases retention balances held in line with contractual terms and conditions which will be agreed prior to commencement of a contract. The supplier retention will be released typically with 50% released upon the issue of the takeover certificate and the remainder released 365 days after the issue of the takeover certificate. This may however vary depending on the size and complexity of the construction work that is being undertaken.
Retention release stages
50% is released upon the issue of the takeover certificate with the remainder released 365 days after the issue of the takeover certificate.
- Retention in all contracts
- No
- Retention in standard terms
- No
- Retention threshold
- Not supplied
- Standard retention rate
- Not supplied
- Retention compared with client
- 114.0%
- Retention compared with payments
- 0.0%
Reported terms and dispute process
- Standard payment terms
MWH Treatment Limited does not have standard payment terms, they range from immediate to 60 days. Payment terms are agreed with suppliers as part of contract negotiations. The most frequently used payment terms in the reporting period were 30 days.
Payment runs are typically on a weekly basis by BACS. - Dispute resolution process
MWH Treatment actively seeks to resolve disputes, typically involving members of the accounts payable along with the procurement and commercial teams and where necessary members of the relevant management team. Where it is not possible to reach agreement, a number of potential dispute resolution methods (for example, mediation, adjudication, expert determination, litigation and /or arbitration) may be used.
Earlier payment reports (11 shown)
- 28.0 average days to pay9.0% outside terms
- 31.0 average days to pay9.0% outside terms
- 28.0 average days to pay10.0% outside terms
- 30.0 average days to pay9.0% outside terms
- 26.0 average days to pay9.0% outside terms
- 26.0 average days to pay10.0% outside terms
- 28.0 average days to pay10.0% outside terms
- 33.0 average days to pay17.0% outside terms
- 36.0 average days to pay18.0% outside terms
- 51.0 average days to pay30.0% outside terms
- 47.0 average days to pay19.0% 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
- MWH TREATMENT LIMITED
- Group submission
- No
- Statement period
- 1 April 2025 – 31 March 2026
- Approved
- 8 May 2026
- Sectors
- Construction, civil engineering and building products Utilities: gas, water and electricity
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
- 7 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 child labour Prohibits discrimination Prohibits confiscation of workers' original identification documents
Training described
Your whole organisation Your suppliers
Worker engagement and working conditions
Civil society organisations Workers within your organisation Workers within your supply chain Businesses in your industry or sector
Social audits
Third party audit arranged by your organisation Unannounced audit
Grievance mechanisms
Using anonymous whistleblowing services, such as a helpline or mobile phone app
Demonstrated progress
Requirement for 90% of all employees to undertake an internally developed e-learning Modern Slavery Awareness training module - 92.5% completed. To attend and support the Supply Chain Sustainability School (SCSS) Modern Slavery Due Diligence Capability Assessment Workshops. MWHT attended and supported the development of the new tool provided for free by SCSS. To hold worker interviews on at least 6 MWHT construction sites. Slave Free Alliance completed them on 4 construction sites.
Reported risks and mitigations
- Risk: Construction workers employed through our sub-contractors
- Area: Within your supply chains
- Tier: Tier 1 suppliers Tier 2 suppliers
- Group: Migrants
- Location: United Kingdom
- Mitigation: Subcontract clauses specifically on modern slavery; Annual communications to the supply chain on modern slavery awareness and MWHT expectations; Toolbox talks; Worker interviews undertaken on higher risk sites (e.g. concrete finishers and ground workers); Guidance provided on company website; Numerous multi-lingual spot the signs posters available and displayed on construction sites which include whistleblowing helpline. Actions identified from worker interviews are addressed.
- Risk: Labour providers - temporary agency workers
- Area: Within your own operations
- Group: Migrants Refugees
- Mitigation: Labour agency assessment process prior to selection; Audits of labour agencies; Terms & Conditions including right to work and anti-slavery requirements; Worker interviews undertaken on higher risk sites; Numerous multi-lingual spot the signs posters available and displayed on construction sites which include whistleblowing helpline. Actions identified from worker interviews are addressed.
- Risk: Cleaning providers for offices and construction site welfare facilities
- Group: Women Migrants Refugees
- Mitigation: Cleaning and security company procurement assessment prior to selection; Worker interviews undertaken on higher risk sites which includes cleaners; Specific audits undertaken on companies where concerns have been raised; Numerous multi-lingual spot the signs posters available and displayed on construction sites which include whistleblowing helpline. Actions identified from worker interviews are addressed.
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
MWH Treatment Limited
Registration Z1797602
- Registered from
- 15 June 2009
- Current end date
- 14 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 Ownership and control
People with significant control
Mwh Uk Acquisitions Limited
- Owns 75% or more of shares
- Controls 75% or more of voting rights
- Can appoint or remove directors
- Country registered
- United Kingdom
- Legal authority
- England And Wales
- Legal form
- Private Limited Company
- Place registered
- Companies House
- Registration number
- 11652932
- Notified
- 2 November 2018
Stantec Treatment Holding Limited
- Owns 75% or more of shares
- Controls 75% or more of voting rights
- Can appoint or remove directors (as a firm)
- Has significant influence or control (as a firm)
- Country registered
- England And Wales
- Legal authority
- Companies Act 2006
- Legal form
- Limited Company
- Place registered
- Companies House
- Registration number
- 05728439
- Notified
- 6 April 2016
- Ceased
- 2 November 2018
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.
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
Major Infrastructure Delivery Framework
ANGLIAN WATER SERVICES LIMITED · updated 17 August 2026
- Tender value
- £1,500,000,000
- Awards
- 2
Wider Ecosystem
NORTHUMBRIAN WATER GROUP LIMITED · updated 25 October 2024
- Tender value
- £8,000,000,000
- Awards
- 47
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
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
Other specialised construction activities n.e.c.
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
2 procurement processes linked by exact GB-COH identifier.
Waste register
1 exact company-number registration.
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
- Detected change
Confirmation statement due date: 2026-08-26 → 2027-08-26
- Confirmation statement
Latest confirmation statement made up to this date
- Accounts
Latest accounts made up to this date
- Company name
Previous name: STANTEC TREATMENT LIMITED
- Company name
Previous name: MWH TREATMENT LIMITED
- Company name
Previous name: BIWATER TREATMENT 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.
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.