If you run a trade subcontracting business in the UK, winning the tender is only half the battle. The real risk begins when the main contractor drops an amended JCT order on your desk. Behind standard-looking covers, bespoke schedules of amendments regularly strip away your statutory rights, creating severe commercial revenue loss before your team even mobilises on site.
1. The 3-Day Delay Notice Condition Precedent (Clause 2.26)
Technical Authority: Under standard JCT Design and Build Subcontract (DBSub 2016/2024) conditions, Clause 2.26 requires a subcontractor to give written notice of delay “forthwith” or within a reasonable time when a Relevant Event occurs. Bespoke amendments systematically replace this wording with a strict condition precedent: requiring formal notice within 3 business days.
Plain English Translation: If another trade blocks your access on Tuesday morning, you must serve a formal contractual notice by Friday afternoon. Mentioning it to the site manager verbally or raising it at a weekly progress meeting does not count. If your written notice lands on Monday morning, your legal right to an extension of time is permanently extinguished.
Financial Risk: Missing the notice deadline leaves your practical completion date unchanged. The main contractor can deduct Liquidated and Ascertained Damages (LADs)—often running from £2,500 to £12,000+ per week—directly from your interim valuations, while you absorb all idle labour and plant hire costs yourself.
2. The Uninsurable CDP Design Trap (Clause 2.19)
Technical Authority: Standard JCT contracts limit a subcontractor’s design obligations to the exercise of reasonable skill and care, matching the statutory standard under the Supply of Goods and Services Act 1982. Main contractor schedules often upgrade this to an absolute “fitness for purpose” warranty.
Plain English Translation: A fitness for purpose clause guarantees that your installation will achieve an outcome regardless of external factors or third-party design faults. Crucially, standard UK Professional Indemnity (PI) insurance policies strictly exclude fitness for purpose liabilities.
Financial Risk: If a specification fails, your insurer will refuse to cover the claim because you agreed to a standard above reasonable skill and care. You are left personally exposed to £45,000+ in uninsured remediation costs and legal claims.
3. Pay-When-Certified & Stretched 60-Day Terms (Section 113)
Technical Authority: Section 113 of the Housing Grants, Construction and Regeneration Act 1996 (HGCRA 1996) expressly outlaws “pay-when-paid” clauses, except in rare upstream insolvency cases. Main contractors frequently draft subtle workarounds that link interim valuations to upstream client sign-offs or stretch payment terms to 60 days.
Plain English Translation: The contractor withholds your monthly valuation on the grounds that the employer’s agent has not yet signed off the main contract certificate. This forces you to act as an uncredited bank for the main contractor’s working capital.
Financial Risk: You carry two to three months of unfunded labour, materials, and fabrication costs. When compounded with arbitrary contra-charges, this triggers severe cash-flow shortages that can bring a trade business to a halt.
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