What AS 4000:2025 actually is

AS 4000 is the General Conditions of Contract, one of Australia's most widely used head-contract forms, sitting between the principal and the head contractor. The 2025 edition is a modernisation, not a rewrite: the core structure that made the form familiar is intact, with updates to reflect current law and the way projects are actually run.

Subcontractors usually sit one level down, under AS 4901 subcontract conditions written to sit back-to-back with an AS 4000 head contract. The related subcontract forms (AS 4901, plus AS 4902 and AS 4903 for design and construct) are expected to be updated too, but at the time of writing they have not been. So you can easily end up on a 2025 head contract flowing down to a 1998-era subcontract, and the two do not always line up.

What changed in the 2025 edition

The headline changes that matter most on site and in the commercial office:

  • Electronic notices are now expressly allowed. Service of notices by email and other electronic means is recognised. Notices you send or receive by email can now count, so check which address and format the contract nominates.
  • Superintendent obligations are tightened. Where an extension of time affects liquidated damages, the superintendent must respond within the set period, with clearer consequences for not doing so.
  • Dispute resolution defaults to litigation. Unlike the 1997 form (which defaulted to arbitration), the 2025 edition ends in court if negotiation fails, with optional ADR steps such as mediation, expert determination or a dispute avoidance board if the parties select them.
  • One combined document. The Formal Instrument of Agreement is now part of the same document as the general conditions, which makes the whole deal easier to read in one place.
  • Payment certificate timing is spelled out. After a progress claim, the superintendent has 14 days to issue a payment certificate.
  • Modernised for current law. Updated to reflect GST (including recipient-created tax invoices), harmonised WHS laws (the contractor can be appointed Principal Contractor) and the Personal Property Securities Act.

What it does not change: Security of Payment

AS 4000:2025 still does not build in state-based Security of Payment (SOP) legislation. Your SOP rights in NSW, QLD, VIC and the other states apply regardless of what the contract says, and they often override it. For example, "pay when paid" clauses are void. Don't rely on the contract alone for payment timing; know your reference dates and response deadlines. Our guide to getting a Security of Payment claim right walks through the traps.

Where subcontractors get caught: back-to-back

When the head contract is on the 2025 edition and your subcontract is on an older form, notice methods, timeframes and definitions can quietly differ. Main contractors also run large contracts teams and tend to amend the standard form to tighten the notice and claims regime in their favour. The base form is only the starting point. The amendments are where risk gets shifted. It's worth knowing the clauses that quietly move risk onto subcontractors before you price the job, not after.

What to check before you sign

  • Which edition is the head contract on, and which form is your subcontract? Are they consistent with each other?
  • How must notices be given? Is email allowed, to whom, and are there deadlines or time bars added by the amendments?
  • The notice and time-bar clauses for delays, EOT and variations: what starts the clock, and how many days you get.
  • The superintendent's role and response times, especially around EOT and liquidated damages.
  • The liquidated damages rate and any cap, plus retention and bank-guarantee amounts and their release triggers.
  • Your Security of Payment reference dates and response timeframes in your state. These sit above the contract.

Protect yourself: the record wins the money

The contract sets the rules, but your records are what recover or protect the money when a delay or variation hits. Keep a running delay log, dated site photos and daily labour and plant records as events happen, so you can meet whatever notice regime your contract sets. When a clause is unclear, raise it with the principal or your own adviser, and use a plain-English clause read from our free tools to spot the notice traps before they cost you.

New edition or old, the outcome is the same: the subbie who notices the clause and keeps the record is the one who gets paid.