Construction Delay Notice to a Subcontractor: Template + Rules
The M&E subcontractor promised the second-floor containment would be done last Tuesday. It is now the following Monday, the ceiling crews are standing down, and the main contract programme is starting to feel it. The site team has had three "we'll catch up" conversations, none of them on paper. This guide covers the letter that should have gone out after the first one — what it must say, and a template you can adapt today.
Why the Letter Matters More Than the Phone Call
When a subcontractor slips, the instinct is a conversation — and the conversation is right, as far as it goes. Most slippages are recovered by working the problem, not by writing about it.
But if the slippage is not recovered, the main contractor ends up holding consequences it will want to pass back: liquidated damages under the main contract, acceleration costs, other trades disrupted. Every one of those recoveries leans on the same question — can the main contractor show the failure was identified, notified in writing, and not cured? Three site conversations and a WhatsApp thread do not answer it. A dated letter does.
There is a fairness function too. A formal notice gives the subcontractor an unambiguous signal that the delay is now a contractual issue, not site noise — and a fixed date to respond with a recovery plan. Plenty of subcontract delays end at that letter, precisely because it was clear.
So send it early — at the first clear slippage on anything that matters, while the letter still reads as programme management rather than the opening shot of a dispute. Then make the call.
Key Takeaway: The phone call works the problem; the letter preserves the recovery. Backcharges, delay damages, and acceleration costs all depend on showing the failure was notified in writing and not cured — so send the notice at the first real slippage, then pick up the phone.
What the Notice Must Contain
Five things, all of them factual:
- The subcontract clause — the provision requiring the Subcontractor to proceed with due diligence or maintain progress against the Subcontract programme.
- The late activities, with dates — each one measured against the Subcontract programme: planned date versus actual or forecast date. This list is the heart of the letter.
- The knock-on effect — which trades, areas, or main-programme activities the delay is hitting.
- A recovery plan demand with a deadline — a specific date, typically five to seven days out, by which the Subcontractor must show how progress will be restored.
- A reservation of rights — the Contractor's entitlement to costs, losses, or damages if the delay continues.
Keep the tone flat. Adjectives about performance impress nobody; a dated, activity-by-activity comparison against the programme does. The letter may one day be read by an adjudicator, and the version that wins is the boring one.
Key Takeaway: Five parts: the progress clause, the late activities with planned-versus-forecast dates, the knock-on effect, a recovery plan demanded by a fixed date, and a reservation of rights. Factual and flat — the letter is doing evidence work.
Delay Notice to a Subcontractor — Copy and Adapt
Replace the brackets. The clause reference is generic because subcontract forms vary — cite your subcontract's own progress clause.
After it goes out, two follow-ups keep it alive: diarise the recovery-plan date and chase it in writing if it passes silent, and keep updating the programme comparison — the before-and-after record is what turns this letter into a backcharge that sticks.
Key Takeaway: One page: the clause, the late activities with dates, the effect, the recovery deadline, the reservation. Then diarise the deadline and keep the programme comparison updated — the follow-through is what makes the notice worth anything.
If the Subcontractor Says It's Not Their Fault
Sometimes the reply is: "we're late because of you — no access, late information, the other trade blocked us." If that is true, the right response from the Subcontractor is not an argument on the phone but its own delay claim notice under the subcontract — in writing, within the subcontract's notice period. And that period is worth checking on both sides: back-to-back subcontracts usually shorten it well below the familiar 28 days, so the main contractor can pass a claim up the chain in time.
For the main contractor there is one reflex to build in: if the true cause sits above you — an Employer variation, late drawings from the Engineer — serve your own notice of claim upstream immediately, inside your 28-day window under the main contract. Sitting on the Subcontractor's claim while you review its merits can close that window and turn a recoverable cost into your own loss.
Key Takeaway: If the delay isn't the Subcontractor's fault, it answers with its own written claim notice under the subcontract — and if the real cause sits above the main contractor, the main contractor serves its own upstream notice of claim straight away, before the 28-day window closes.
Common Mistakes
- Managing by conversation. Weeks of verbal chasing with nothing on paper, then a dispute in which the file shows no notified delay at all.
- An angry letter instead of a precise one. Complaints about attitude and manning where a dated list of late activities should be.
- No recovery deadline. Asking the Subcontractor to "improve progress" without a date gives the letter no teeth and no follow-up trigger.
- Sending it too late. A first notice served when the delay is already critical reads as dispute-opening, arrives with a thin paper trail, and leaves no room for the recovery plan to work.
- No follow-through. The recovery-plan date passes in silence and nothing happens. An unenforced notice teaches the Subcontractor the letters mean nothing.
- Wrong address. Subcontracts often name a specific recipient and method for notices. Hand-delivery to a foreman may not count.
Key Takeaway: The recurring failures: chasing verbally with nothing in writing, venting instead of listing late activities with dates, demanding recovery with no deadline, serving the first notice too late, letting the deadline pass unenforced, and sending it to the wrong address.
Frequently Asked Questions
Why send a formal delay notice to a subcontractor instead of just calling them?
Because the call fixes today and the letter protects the next twelve months. If the subcontractor's delay later costs the main contractor time or money — liquidated damages under the main contract, acceleration costs, backcharges — the main contractor will need a written record showing the failure was identified, notified, and not cured. Phone calls and site conversations leave no such record. Send the letter, then make the call.
What should a delay notice to a subcontractor contain?
Five things: the subcontract clause that requires the subcontractor to proceed with due diligence or maintain progress; the specific activities that are late, measured against the subcontract programme; the knock-on effect on the main works; a clear request for a recovery plan by a stated date; and a reservation of the main contractor's rights, including any backcharge or damages entitlement. Keep it factual — the letter may one day be read by an adjudicator.
When should the first delay notice go out?
At the first clear slippage against the subcontract programme on anything that matters — not after weeks of verbal chasing. An early notice is easier to write and easier to receive: it reads as programme management, not as the opening shot of a dispute. Waiting until the delay is critical produces a harsher letter, a weaker paper trail, and less time for the recovery plan to work.
Does the notice automatically entitle the main contractor to backcharges?
No. The notice preserves the right; it does not prove the claim. Recovering delay costs from a subcontractor still requires showing the delay was the subcontractor's fault, that it actually caused the loss, and what the loss was — which is why the notice should be followed by records: updated programme comparisons, site diary entries, and any second notice if the recovery plan is missed.
What if the subcontractor says the delay is not its fault?
Then the right response from the subcontractor is its own delay claim notice under the subcontract — in writing, within the subcontract's notice period, which is often shorter than the 28 days the main contract allows. And if the true cause sits above the main contractor — an Employer variation, late drawings — the main contractor must serve its own notice up the chain within its 28-day window under the main contract. Whoever is right, the answer arrives by letter, not by argument on the phone.
Authoritative Sources
This guide reflects the FIDIC Conditions of Contract and established construction-law guidance. For the primary materials, see:
- FIDIC Conditions of Contract — the official contract suite published by the International Federation of Consulting Engineers, including the Conditions of Subcontract designed to operate back-to-back with the Red Book.
- SCL Delay and Disruption Protocol — the Society of Construction Law's guidance on notice, contemporaneous records, and the assessment of delay.
About the Author
Maisam Jiwani is a Project Director with 15 years' experience on major infrastructure and energy projects administered under FIDIC contracts. He writes from first-hand experience serving notices and managing contractual claims on live projects.