Australian Standard Contracts
AS 4901 Subcontract Review
AS 4901-1998 is the subcontract that sits beneath an AS 4000 head contract. Review for head contractors passing risk down and subcontractors taking it on, from a solicitor and registered architect.
AS 4901-1998, the General Conditions of Subcontract, is the construct-only subcontract companion to AS 4000. It is used between a head contractor and its subcontractors, so the obligations the head contractor accepts under AS 4000 can be passed down the contract chain on a consistent basis.
In practice the head contract is almost always amended by special conditions, and the subcontract is where those amendments are either carried through or lost. An unamended AS 4901 under a heavily amended AS 4000 leaves the head contractor holding risks it cannot pass on, while a subcontract that passes down more than the head contract imposes can leave a subcontractor carrying risk it has not priced.
For subcontractors, the subcontract also has to be read against security of payment legislation. That legislation gives a subcontractor statutory rights to claim progress payments and to go to adjudication, and it renders pay-when-paid provisions of no effect, whatever the subcontract says.
Where Christopher can help with AS 4901
Whether you are issuing AS 4901 subcontracts or being asked to sign one, the questions are the same: does the subcontract line up with the head contract, and is the risk it allocates priced and insurable? Here is where Christopher can help.
Flow-down from the head contract
Checking that the AS 4901 subcontract and its special conditions carry through the head contract amendments on time, payment, defects and security, so there is no gap in the chain.
Subcontractor review before signing
A review for subcontractors of the terms that decide whether a package makes money: payment terms, variations, time bars, liquidated damages, security and indemnities.
Payment and security of payment
Advice on progress claims and payment schedules under the subcontract and the security of payment legislation that sits above it, from a registered adjudicator who has determined more than 180 adjudications.
Special conditions
Drafting and reviewing AS 4901 special conditions so they do what the parties intend and stay consistent with the head contract.
Key features of AS 4901
Subcontract companion to AS 4000
AS 4901 belongs to the AS 4000 family and mirrors its structure, which makes it easier to keep head contract and subcontract aligned when both are used on a project.
Construct only
Like AS 4000, it is a construct-only form: the subcontractor builds to a design it is given. Where the subcontractor also designs, the design and construct subcontract AS 4903 is the usual companion to AS 4902.
Back-to-back by intention, not by default
The standard form does not know how the head contract has been amended. Keeping the two in step depends on the special conditions written for the subcontract.
Statutory payment rights apply
Security of payment legislation in each state and territory sits above the subcontract, giving subcontractors rights to claim payment and to adjudication that cannot be contracted out of.
When AS 4901 is used
- Trade packages beneath an AS 4000 head contract
- Construct-only subcontracts on commercial and civil projects
- Head contractors wanting a standard form aligned with their head contract
- Subcontractors asked to sign an amended AS 4901 package
Common questions about AS 4901
What is AS 4901?
AS 4901-1998 is the Australian Standard General Conditions of Subcontract. It is the construct-only subcontract companion to AS 4000, used between a head contractor and its subcontractors so the head contract obligations can be passed down the chain on a consistent basis.
Is AS 4901 back-to-back with AS 4000?
It is designed to align with AS 4000, but it is only back-to-back if the special conditions make it so. Head contracts are almost always amended, so an unamended subcontract under an amended head contract will leave gaps. Each package needs its special conditions checked against the head contract actually signed.
Can an AS 4901 subcontract make payment conditional on the head contractor being paid?
Security of payment legislation in each Australian state and territory renders pay-when-paid provisions of no effect, so a subcontractor’s right to progress payments does not depend on whether the head contractor has been paid by the principal. The detail varies between jurisdictions, so the relevant Act should be checked for the project.
What is the difference between AS 4901 and AS 4903?
AS 4901-1998 is the construct-only subcontract, the companion to AS 4000. AS 4903-2000 is the design and construct subcontract, the companion to AS 4902. Which one fits depends on whether the subcontractor is building to a design it is given or also designing its part of the works.
Has AS 4901 been updated alongside AS 4000:2025?
AS 4901-1998 remains the edition in use. Where the head contract adopts AS 4000:2025, the subcontract needs checking against the updated head contract mechanisms, particularly dispute resolution, so the two still line up.
Keep reading
Australian Standard contracts overview
How the AS suite fits together and which standard form suits your project.
Australian Standard contract adviceAS 4000 contract lawyer
The construct-only head contract that AS 4901 sits beneath.
AS 4000 contract review and adviceAS 4902 contract lawyer
The design and construct head contract, with AS 4903 as its subcontract.
AS 4902 contract review and adviceSecurity of payment
Payment claims, payment schedules and adjudication for subcontractors and head contractors.
Security of payment adviceContract review before signing
A dual-qualified review of the contract and its special conditions before you commit.
Have a contract reviewed before signingDiscuss your contract
Talk through your standard form contract with a solicitor who is also a registered architect.
Contact Christopher LarcosGet advice on your AS 4901 contract
Before you issue or sign an AS 4901 subcontract, check it against the head contract it sits under. Christopher can review the subcontract and its special conditions and flag the gaps and unpriced risks before they become a dispute.