How to win work as a subcontractor: getting onto tender lists
The short answer
To get subcontract work, make your firm quick to verify. Buyers and estimators check sectors, contract values, accreditations, insurance, recent schemes and your Companies House record before sending a pre-qualification questionnaire. Register for CIS (contractors deduct 30% from unregistered subcontractors and 20% from registered ones, according to HMRC), hold a Common Assessment Standard or SSIP certificate, and publish a capability statement anyone can download.
What main contractors check before adding a subcontractor to a tender list, and the registrations, documents and web pages that get you invited to price.
Subcontract work rarely comes from advertising. It comes from being on a tender list, and tender lists are built by buyers, estimators and quantity surveyors who run quick checks on firms they have not used before.
This guide is for UK subcontractors and specialist trades who want to know how to get subcontract work from main contractors: what a buyer checks, which registrations matter, what to publish, where public sector work is advertised and how to keep getting asked to price.
A subcontractor's website is part of that check. Good contractor website design puts sectors, contract values, accreditations and recent schemes where a buyer can find them in under a minute.
How do subcontractors get onto tender lists?
Subcontractors get onto tender lists by passing three filters in order: a quick desk check by a buyer or estimator, a pre-qualification questionnaire (PQQ), and then a competitive price when invited. Most of the work is making the first two filters easy.
A buyer's desk check on an unfamiliar subcontractor usually looks like this:
- Search the company name.
- Open the subcontractor's website and look for sector relevance and scale.
- Look for accreditations and insurance levels.
- Check Companies House for filing history and accounts.
- Decide whether to send a PQQ or add the firm to the list for the next package.
The desk check is quick because buyers have other names to choose from. If a subcontractor's website makes the second step slow, the buyer moves on and the subcontractor never finds out why.
The PQQ that follows is increasingly standardised. Build UK's Common Assessment Standard is an industry-agreed question set accepted by many contractors and clients, and Build UK says public sector bodies should use it to pre-qualify suppliers.
What do main contractors check before adding a subcontractor?
Main contractors check seven things before adding a subcontractor to a tender list: sectors, contract values, accreditations, insurance, coverage, recent comparable schemes and the Companies House record.
| Check | What the buyer wants to see | Where a subcontractor should show it |
|---|---|---|
| Sectors | Education, healthcare, industrial, residential, retail, commercial fit-out | Homepage and a sectors page |
| Contract values | A band is fine, for example "packages from £50k to £800k" | Homepage and capability statement |
| Accreditations | CHAS, Constructionline, SafeContractor, Common Assessment Standard, ISO and trade bodies, with certificate numbers and expiry dates | An accreditations page, kept current |
| Insurance | Employers' liability, public liability and, where design is involved, professional indemnity, with cover levels | Accreditations page and capability statement |
| Coverage | The regions or counties the firm genuinely travels to | Homepage and contact page |
| Recent schemes | Client, main contractor, value, programme, scope and photos | One case study page per scheme |
| Company record | Filing history, accounts and directors | Companies House, so keep filings up to date |
A subcontractor website that shows only a slideshow and a contact form is a brochure, and a brochure fails the check. Every item in this subcontractor checklist should be answerable from the website without phoning the office.
Required insurance levels vary by package and contractor, so state your actual cover rather than a vague "fully insured".
What should a subcontractor capability statement include?
A subcontractor capability statement is a one- or two-page document that answers a buyer's first questions in one place. It should cover:
- Who the firm is and what packages it delivers
- Sectors worked in
- Contract value band
- Accreditations, with certificate numbers and expiry dates
- Insurance types and cover levels
- Key personnel and their qualifications
- Three reference projects with values and dates
- Contact details for the person who handles tenders
Publish the capability statement on the website as a downloadable PDF that does not ask for an email address. A buyer working to a tender deadline will not fill in a form to get it, and gating it costs more than the email address is worth.
Date the capability statement and update it whenever an accreditation renews. An expired certificate date raises exactly the doubt the document is meant to remove.
How should subcontractors write case studies for supply chain work?
Subcontractor case studies work best as short, structured write-ups, one per scheme, rather than a photo gallery. Each case study should let a buyer judge whether the subcontractor can handle a package like theirs.
- Client and main contractor, named only with their permission
- Contract value or value band
- Programme length
- Scope of the subcontract package
- Constraints worked around, such as an occupied site, phased handover or restricted access
- Photos of the finished work and of work in progress
A handful of structured case studies does more for supply chain work than pages of marketing copy, because they answer the buyer's real question: has this firm done a job like mine? Use a value band if the figure is confidential.
One page per scheme also gives the website pages that match how buyers search, such as "M&E subcontractor school refurbishment Leeds". For a wider pipeline, pair case studies with the ideas in how to get more construction leads.
Which registrations and accreditations do UK subcontractors need?
A UK subcontractor should register for the Construction Industry Scheme (CIS) with HMRC, must hold employers' liability insurance once it employs staff, and usually needs CSCS cards for operatives. Health and safety pre-qualification, such as an SSIP scheme or the Common Assessment Standard, is not a legal requirement, but many main contractors ask for it.
| Registration | What it is | Why it matters for subcontract work |
|---|---|---|
| CIS registration | HMRC scheme for contractor payments to subcontractors | Contractors deduct 20% from registered subcontractors and 30% from unregistered ones; gross payment status means no deduction at source |
| Employers' liability insurance | Legally required once a business employs staff, with some exemptions | At least £5 million of cover from an authorised insurer; GOV.UK says the fine is £2,500 for every day without proper cover |
| CSCS card | Proof a site worker has the right training and qualifications | Commonly checked at site induction |
| SSIP member scheme, such as CHAS | Health and safety assessment recognised by other SSIP schemes ("deem to satisfy") | Cuts repeat assessments for different clients |
| Common Assessment Standard | Build UK's industry-agreed pre-qualification, certified by recognised assessment bodies including Achilles, Constructionline and Veriforce CHAS | Accepted by many contractors; public sector bodies are told to use it |
| Trade registration | For example Gas Safe Register for gas work, NICEIC or NAPIT for electrical work, NFRC for roofing | Gas Safe registration is a legal requirement for gas work; the others show competence to buyers |
For a closer look at one of the most common schemes, read CHAS accreditation explained, which covers cost, process and when it helps. Scheme fees change, so check the provider's own site for current prices before budgeting.
Where can subcontractors find public sector tenders in the UK?
Subcontractors can search UK public sector tenders for free on Find a Tender, the government's central digital platform under the Procurement Act 2023, which launched in its new form on 24 February 2025. Suppliers register once, store their core company details and set up alerts for their trade and region.
Contracts Finder still lists government and agency contracts in England over £12,000 including VAT, so check both services. Scotland, Wales and Northern Ireland also run their own portals: Public Contracts Scotland, Sell2Wales and eTendersNI.
Public construction contracts are often won by a main contractor who then lets the packages. Find a Tender also shows awarded contracts, so a subcontractor can see which main contractors have just won schools, hospitals or housing schemes locally and send their supply chain teams a capability statement.
Main contractors also run their own supply chain portals. Registering on them and on Constructionline is administrative work, and often the step a busy firm never gets round to.
How do subcontractors get asked to price again?
Subcontractors get asked to price again by returning clear, complete quotes on time, with exclusions and assumptions stated plainly. Estimators decide who gets invited, so build relationships with estimators, not only buyers.
Quote quality is an underrated business development tool: a tidy, unambiguous quotation makes an estimator's job easier, and estimators remember who saves them time.
- Respond by the deadline, or decline early so the estimator can invite someone else.
- Price to the drawings and specification issued, and list the revision numbers used.
- State exclusions, assumptions and attendances (scaffold, welfare, skips, power) clearly.
- Give the programme duration and lead times for key materials.
- Name one contact who can answer questions the same day.
Pricing accurately matters as much as presenting well. The guide how to price building work covers what to include and the costs that are easy to miss.
Why do buyers check Companies House before using a subcontractor?
Buyers check Companies House to confirm that a subcontractor is a real, active company that files on time and looks able to carry the contract value. The register is free to search, so a subcontractor should assume every buyer will look.
Late filings, an odd-looking dormant year, an overdue confirmation statement or accounts that suggest the firm cannot carry the package value can all get a subcontractor filtered out without a conversation.
If filed accounts understate what the business can handle, for example after a growth year not yet filed, be ready to explain it, and make sure the website's turnover and staff figures match the register.
Sole traders and partnerships do not appear on the Companies House register, so for those firms the website, insurance certificates and references carry more of the weight.
Is your firm ready for tender lists? A 10-point checklist
A subcontractor is ready to approach main contractors when a buyer can confirm all ten points in this ConstructionWebDesign.uk checklist from the website and the documents it links to.
- Sectors worked in are named on the homepage.
- A contract value band is stated.
- Accreditations are listed with certificate numbers and expiry dates.
- Insurance types and cover levels are stated.
- The regions covered are clear.
- At least three structured case studies are published.
- A capability statement downloads without an email form.
- CIS registration is in place.
- Companies House filings are up to date.
- A named tender contact, phone number and email address are on every page.
Decision rule: if a buyer cannot find a subcontractor's sectors, contract value band, accreditations and insurance from the homepage in about a minute, fix the website before registering on more portals.
How ConstructionWebDesign.uk can help
ConstructionWebDesign.uk is a UK web design agency that only builds websites for construction companies and trades, including main contractors and building firms. The Website package is £1,000, a one-off fixed price with no subscription, and includes custom domain and hosting setup, service pages, mobile-first design and on-page local SEO. Sites go live in 7 days from the discovery call, and the client owns the website. See contractor website design for how ConstructionWebDesign.uk lays out sectors, accreditations and case studies, or book a free 30-minute call.
Frequently asked questions
Do I need CHAS or Constructionline to get subcontract work?
CHAS and Constructionline are not legal requirements for subcontract work, but many main contractors ask for an SSIP scheme or a Common Assessment Standard certificate before adding a firm to their supply chain. Check which schemes your target contractors accept, then choose one of those. One recognised certificate is worth more than several nobody asks for.
Do subcontractors have to register for CIS?
Subcontractors working for a contractor should register for the Construction Industry Scheme (CIS) with HMRC. Registration is not compulsory, but contractors must deduct 30% from payments to unregistered subcontractors, compared with 20% for registered ones. Subcontractors who meet HMRC's conditions can apply for gross payment status, which means contractors pay them without any deduction at source.
What is a capability statement for a subcontractor?
A capability statement is a one- or two-page summary that lets a buyer assess a subcontractor quickly. It lists sectors, contract value band, accreditations with expiry dates, insurance levels, key personnel, three reference projects and contact details. Publish it as a free PDF with no email form in front of it.
Where can I find subcontract work in the UK?
Subcontract work in the UK is found mainly through main contractors' approved supplier lists and portals, Constructionline, and public sector platforms such as Find a Tender and Contracts Finder. Scotland, Wales and Northern Ireland use Public Contracts Scotland, Sell2Wales and eTendersNI. Award notices on Find a Tender show which main contractors have recently won work nearby.
How long does it take to get on a main contractor's approved list?
The time it takes to get on a main contractor's approved list varies by contractor and by how ready your paperwork is. Each contractor runs its own pre-qualification, and some only review new subcontractors when a package comes up. Having a current Common Assessment Standard or SSIP certificate, insurance documents and a capability statement ready removes the delay of gathering documents on request.
Sources
- GOV.UK: What you must do as a Construction Industry Scheme (CIS) subcontractor
- GOV.UK: Employers' liability insurance
- GOV.UK: Central Digital Platform factsheet (Find a Tender)
- GOV.UK: Contracts Finder
- Companies House: search the register
- Build UK: Common Assessment Standard
- SSIP: Safety Schemes in Procurement
- CSCS: Construction Skills Certification Scheme
- CHAS
- Constructionline
- Gas Safe Register
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