How to Become a Subcontractor in the UK: Requirements, PQQs and Winning Work from Builders

Becoming a subcontractor in the UK means proving to a builder that you are safe to put on their site and their paperwork: a registered business, CIS status with HMRC, the right insurance, a health and safety accreditation and references from finished jobs. That makes you eligible. It does not make you busy. The subbies who are never short of packages are the ones a buyer already knows when the tender list gets written, and that list is written earlier than most people think.

This is the process end to end, from the paperwork every builder checks to the part nobody writes down: how to be on the shortlist before the tender documents exist. If you want the list of where to register with the big names, that lives in the tier-1 supply chain registers map. This post is about what they look for once you get there.

What builders check before they let you near a package

We track 557 UK routes into construction work, from council portals to main contractor registers, and the requirements on them are remarkably consistent. The form changes, the five things being filtered do not.

1. 01A real business. Sole trader, partnership or limited company, with a UTR and, if you are over the threshold, a VAT number. A limited company is not required, but some buyers ask for two or three years of accounts, which a new company cannot produce.
2. 02CIS status. Registered as a subcontractor with HMRC at the very least, so the builder deducts 20% not 30%. Gross payment status is better and is what serious buyers like to see.
3. 03Insurance at a stated level. Employer's liability if you employ anyone (a legal minimum of 5 million pounds), public liability, and on some packages contractors' all risk or professional indemnity.
4. 04Health and safety proof. An SSIP accreditation (CHAS, SMAS, SafeContractor and others) or a Constructionline membership, plus method statements and risk assessments you can produce on request.
5. 05Evidence you can do the job. References, photographs and named contacts from comparable finished work, and CSCS cards for everyone going on site.

CIS: register before you invoice anyone

Under the Construction Industry Scheme, a contractor paying you for construction labour must verify you with HMRC and deduct tax at source. If you are registered as a subcontractor the deduction is 20%. If you are not, it is 30%. On a 10,000 pound labour invoice that is 1,000 pounds a month of cash flow you hand HMRC for nothing, so register before the first job.

Gross payment status removes the deduction entirely. HMRC applies three tests: a business test (you run a construction business through a UK bank account), a turnover test and a compliance test. The turnover test is at least 30,000 pounds a year of construction turnover, excluding VAT and materials, for a sole trader; for partnerships and companies it is 30,000 per partner or director, or 100,000 across the business. The compliance test looks at your record of filing and paying on time, and since April 2024 it includes VAT.

From April 2026 HMRC can also cancel gross payment status immediately where it suspects fraud, with a five-year bar on reapplying. In practice that means late returns and sloppy VAT now cost more than a penalty: they cost you the status builders look for.

Insurance: what is legal, and what builders actually ask for

Here is the detail most guides get wrong. Most registration forms do not set a minimum at all. Across our 557 routes, the typical portal asks you to declare your insurer, policy number, expiry date and limit, and the actual minimum is set later, per contract, in the tender pack. Fewer than one route in a hundred names a fixed figure at sign-up. So do not buy 10 million of cover to fill in a form. Buy what your current work needs, know what an uplift costs, and be ready to raise it the day a package demands it.

Accreditations and PQQs: answer them once, properly

A pre-qualification questionnaire is how a buyer decides who is allowed to price. Private builders use their own, or outsource the job: Constructionline is named on 103 of the 557 routes we track, and an SSIP scheme such as CHAS, SMAS or SafeContractor on 151. The point of those schemes is that you answer the health and safety, financial and policy questions once and the builder trusts the badge. Which badge is worth paying for depends on who you want to work for; what compliance really costs a small contractor runs the numbers.

Public work changed in 2025. The Procurement Act 2023 went live on 24 February 2025 and replaced the standard selection questionnaire with the Procurement Specific Questionnaire. You register on the Central Digital Platform, answer the core supplier information once, and share it with every public buyer. Councils and housing associations then add their own conditions on top for each contract.

Whatever the form, the answers that lose you a place are the vague ones. Write these once and reuse them:

• A health and safety policy signed and dated in the last 12 months, plus a named competent person.
• Three references from comparable jobs with a name, number and contract value, and permission to call them.
• A trade and region statement that is honest. Claiming every trade in every county reads as a firm that does none of them well.
• Capacity in numbers: how many operatives, what size of package, how fast you can mobilise.
• Environmental and quality statements short enough to be read. One page each.

The real play: get shortlisted before the tender goes out

Everything above makes you eligible. None of it makes you invited. A builder pricing a job does not advertise its packages to the world; its estimator sends enquiries to a short list of subcontractors it already trusts, often three to five per trade, while the builder is still bidding for the main contract. If your name is not in their system on that day, the paperwork you filed does nothing for that job.

The register makes you visible. A person who has your number makes you invited.

Contractor Club

So the work is relationship work, done before there is anything to tender:

1. 01Find the estimators and package buyers, not the generic inbox. Regional offices of main contractors have named estimating and procurement staff. A short, specific introduction (your trade, your area, your package size, one photo of a finished job) to the right person beats a hundred cold registrations.
2. 02Turn up where buyers look for supply chain. Main contractors run supplier days and meet-the-buyer events, especially when they win a large framework and need local subcontractors to hit social value targets.
3. 03Price the enquiries you get, every time. An estimator who sends you three enquiries and gets three prices back on time puts you on the next list. One who gets silence takes you off it.
4. 04Read the award notices. When a builder wins a public contract, the award is published, with the winner's name, on Find a Tender and Contracts Finder. That builder now has packages to fill and a deadline to fill them. A message to their buyer the week the award lands is the most timely approach you will ever make; the award-notice play sets it up as a weekly routine.

Where to apply first

Of the 557 routes we track, 253 accept an open sign-up, 119 go through a platform such as Constructionline or Builder's Profile, 73 charge a fee and 40 are invitation-only. Order matters, because one badge opens many doors:

• Start with the free, open routes in your region: council and housing association portals and the main contractor forms that a person actually reads. The tier-1 registers map sorts all 24 majors by door type.
• Add the badge your target builders name. If three of the builders you want all point to Constructionline, that is the one to buy; if they ask for any SSIP scheme, the cheapest acceptable one does the job.
• Go after the repair and maintenance pipelines, which buy subcontract labour all year rather than per project: managing agents' approved contractor lists and the insurance repair networks both run on approved subcontractors.
• Then work the relationships with the estimators and buyers at the builders who have just won work near you.

Once the work comes in, the other half of the job is pricing it so it pays. What subcontractors get paid in the UK covers day rates and price work from the other side of the table, which is worth reading before you quote a builder.