JCT Contracts Explained: A 2026 Guide for UK Builders and Contractors
The short answer
JCT contracts are the UK's standard building contracts. Pick the form by who designs, how complex the job is and whether the client is a homeowner, then check payment, variations, delay and retention before you sign.
- JCT is a family of standard forms; the current edition is 2024, and the 2016 edition was withdrawn from sale on 31 March 2026.
- Four forms cover most builders: Home Owner, Minor Works, Intermediate, and Design and Build.
- The form is only the start. Payment dates, variations, extensions of time and retention decide whether you get paid.
- For private clients, Sviat Jay advises his mentees to use their own contract instead of a JCT form.
A JCT contract is the standard building contract most UK builders meet sooner or later. Here's which form fits your job and the clauses that decide your cash. If a contract is on your desk now, book a free strategy call.
What a JCT contract is
A JCT contract is a ready-made building contract. The Joint Contracts Tribunal has published standard forms since 1931. You will meet one on a tender, from an architect, or from a commercial client.
A standard form saves both sides from writing a contract from scratch. It sets out:
- The work and the price. Drawings, specification and the contract sum.
- Time. Start date, completion date and what happens if you finish late.
- Changes. How the client instructs extra or different work and how it is valued.
- Payment. When you apply, when they must pay, what they can hold back.
- Risk. Insurance, defects, termination and disputes.
The current edition is JCT 2024. The 2016 edition was withdrawn from sale on 31 March 2026, with a transition period to 31 December 2026. Jobs already signed on 2016 forms carry on, but price new work on 2024 forms.
This page is general information, not legal advice. Have any contract you sign reviewed by a construction solicitor.
The main JCT forms and who each is for
JCT publishes dozens of documents, but four families cover most small and mid-sized builders. A fifth, the Standard Building Contract, is for large projects.
| Form | Typical job | Who designs | Payment structure | Price on JCT store (Oct 2026) |
|---|---|---|---|---|
| Home Owner (HO/B, HO/C 2021) | Extensions and alterations for a homeowner | Homeowner (or their consultant) | Lump sum incl. VAT, on completion or agreed stages | £40 / £46 + VAT |
| Minor Works (MW / MWD 2024) | Simple, low-risk work | Client's team (MWD: you design defined parts) | Lump sum, monthly interim payments | £100 + VAT |
| Intermediate (IC / ICD 2024) | Medium jobs, moderate complexity | Client's team (ICD: you design defined parts) | Lump sum, monthly interim payments | £178 + VAT |
| Design and Build (DB 2024) | You complete the design and build it | You, from the client's requirements | Lump sum, interim stage or periodic payments | £204 + VAT |
| Standard Building Contract (SBC 2024) | Large or complex projects | Client's team | Lump sum or quantities-based | £204 + VAT (SBC/Q) |
Home Owner contracts are consumer contracts. The Construction Act's payment and adjudication rules don't apply to work on a home the client lives in. So JCT builds its own adjudication rules into the Home Owner forms.
For a side-by-side of the three forms builders argue about most, read JCT Minor Works vs Intermediate vs Design and Build.
Problems like this usually trace back to cash and contracts. Take the free 4-minute Construction Business Scorecard: 18 questions on your pipeline, sales, pricing, cash flow and systems, with your weakest area shown first.
How to choose the right form
Value alone should not decide the form. Lawyers who draft these contracts point to four questions instead:
- Who is the client? A homeowner living in the property → Home Owner contract (or your own consumer terms). A business or developer → MW, IC, DB or SBC.
- Who designs? The client's architect designs everything → MW, IC or SBC. You design part → MWD or ICD. You design it all → DB.
- How complex is it? Named specialists, bills of quantities, phased handovers or detailed delay rules push you up from Minor Works to Intermediate.
- How much risk will the client carry? A client who wants one party responsible for everything will push for Design and Build.
Choose the form before tender. Switching forms after pricing, for example from Minor Works to a bigger form, causes delay and usually raises the contract sum.
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The clauses that decide whether you get paid
Every JCT form deals with the same handful of money mechanisms. Read these before anything else.
- Payment dates. When you apply, when the due date falls and when final payment is due. Outside homeowner work, the Construction Act lets you suspend work for non-payment after at least seven days' notice. It also makes "pay when paid" clauses ineffective except on insolvency.
- Variations. Who can instruct a change, in what form, and how it is valued. No written instruction usually means a fight at the final account. See how to get variations paid.
- Extensions of time. Which events (the "Relevant Events") give you more time. The 2024 Intermediate and Design and Build forms added epidemics and changes in law; Minor Works stays very simple here.
- Late completion. Liquidated damages: a fixed sum per week you are late. Check the rate against your margin before you sign.
- Retention. Money held back from each payment. Typically 5%: half released at practical completion, half after a defects period that is usually 12 months.
- Practical completion and defects. When the job counts as finished, and how long you must come back to fix defects.
- Disputes. Adjudication, then arbitration or court. On commercial work you have a statutory right to adjudicate.
Signing the client's "amended JCT" without reading the schedule of amendments. Clients commonly change extension-of-time events, loss and expense and retention, and those changes move risk onto you.
Pros and cons of JCT for a contractor
JCT is a fair, well-known starting point. It is not written for you.
| For you | Against you |
|---|---|
| Clients, architects and lenders know it, so it speeds up signing | It is written to be balanced, not to protect the contractor |
| Clauses have been tested over many disputes | Long documents that small clients rarely read or follow |
| Clear procedures for payment, variations and delay | Commercial clients often add schedules of amendments that shift risk back to you |
| Cheap: £40 to £204 + VAT per form | You can fill in JCT On Demand forms but not change the JCT text |
| Required on many tenders and frameworks | Sviat's view: it does not protect your client relationships or your supply chain; that needs separate agreements |
That last point is where Sviat Jay, founder of BizMentor and owner of the London contractor Craftex, parts company with JCT for private work.
Why Sviat advises bespoke contracts for private clients
In his one-to-one mentoring, Sviat advises owners to use their own contracts, especially with private clients, instead of a JCT form. His reason: a contract written for your business can strengthen your position as the contractor. A standard form only aims to be fair to both sides.
He also tells every mentee to sign non-solicitation and non-compete agreements with everyone on the job: architects, designers, consultants and subcontractors. Without them, either a subcontractor takes your client, or your client hires your subcontractor directly. Right now Sviat has two live cases of clients trying to go around him.
Read the full argument in JCT vs bespoke building contracts for private clients. It covers what a contractor-friendly contract needs and where consumer law draws the line. Want your own contract set up properly? Book a free strategy call. For the agreements themselves, see non-compete and non-solicitation agreements in construction.
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When you must use JCT anyway
You will not always choose the contract. Use the client's form when:
- You are tendering. Main contractors, developers and public clients usually fix the form. Price the risk in their amendments, or qualify your tender.
- A lender or funder requires it. Banks and funders often expect a JCT form with collateral warranties.
- The architect administers the job. Many architects will only administer a form they know.
In each case, read the contract particulars and the amendments, and get a construction solicitor to check anything that changes payment, time or liability. If you need help running valuations, variations and final accounts under JCT, that is what our commercial management service does.
Before you sign a JCT contract
This guide is general information as of October 2026 and not legal advice. Have any contract reviewed by a construction solicitor before you sign it.
Before you sign
- The form fits the job: client type, who designs, complexity
- It is the 2024 edition, and you have read every amendment
- Payment dates, retention % and release dates are written down
- The variation procedure needs a written instruction before you start
- Liquidated damages per week are affordable against your margin
