SOPA (Security of Payment Act)

SOPA is the industry shorthand for the Security of Payment Acts that exist in every Australian state and territory, providing contractors and subcontractors a fast-track statutory pathway to enforce unpaid progress claims. Each state has its own version with subtle differences in timing, claim form, reference dates, and adjudicator panels, but they share a common philosophy: pay now, argue later: adjudicators make interim binding cashflow decisions in 8-12 weeks, and either party can litigate the underlying dispute separately. Verified per current state legislation (2026-05-16).

State-by-state SOPA legislation:

Jurisdiction	Act	Style
NSW	Building and Construction Industry Security of Payment Act 1999	East Coast
VIC	Building and Construction Industry Security of Payment Act 2002	East Coast
QLD	Building Industry Fairness (Security of Payment) Act 2017 (BIF Act)	East Coast, trust-mechanism enhanced
SA	Building and Construction Industry Security of Payment Act 2009	East Coast
TAS	Building and Construction Industry Security of Payment Act 2009	East Coast
ACT	Building and Construction Industry (Security of Payment) Act 2009	East Coast
WA	Construction Contracts Act 2004	West Coast
NT	Construction Contracts (Security of Payments) Act 2004	West Coast

East Coast vs West Coast SOPA models:

Feature	East Coast (NSW, VIC, QLD, etc.)	West Coast (WA, NT)
Trigger	Payment claim served by claimant	Dispute notice + payment dispute
Respondent’s mandatory schedule	Payment schedule must be issued within 10-14 days (or deemed admission)	No mandatory schedule; respondent’s silence less consequential
Adjudicator’s scope	Strictly the payment claim and any payment schedule reasons	Broader; may consider any payment dispute
Default position	If no payment schedule: claimant wins by default	Default rules less harsh; less risky for respondent to ignore claim
Used by	Most subbies in eastern states	Less commonly used in WA/NT than expected

The standard SOPA cashflow:

1. Subbie does work → Payment claim issued
                          ↓
2. Head contractor responds: Payment schedule (or deemed admission if silent within 10-14 days)
                          ↓
3. If unpaid: Adjudication application within 10 BD typical
                          ↓
4. Adjudicator's determination within 10 BD of response
                          ↓
5. Pay or have judgment debt registered (s.25 cert in NSW)
                          ↓
6. Garnishee, writ, charging order, statutory demand if unpaid

Total elapsed time: 8-12 weeks to enforceable judgment.

Critical SOPA timings (NSW):

Action	Time limit
Payment claim	Issued at any reference date (typically end of month); progress on a project
Payment schedule	10 business days after receiving payment claim (or as contract specifies, whichever shorter)
Adjudication application	Within 10 BD of payment schedule (or due-but-not-served date)
Adjudicator acceptance	Around 4 BD
Adjudication response (respondent)	Later of: 5 BD after application, OR 2 BD after acceptance
Determination	Within 10 BD of response
Payment of adjudicated amount	Within 5 BD of determination
Certificate registration in court	At any time after payment date passes

Who is covered by SOPA:

Party	Covered under SOPA?
Subbie (commercial relationship)	Yes; primary beneficiary
Subbie’s subbie (sub-subbie)	Yes
Head contractor against principal	Yes
Owner-builder against engaged builder	NSW: NO (HBA pathway instead); other states: varies
Owner against builder (residential)	NSW: NO since 2014; QLD: NO; VIC: limited
Cleaner, security guard, etc.	Yes, if construction-related

In NSW the owner-occupier exclusion (since 2014) was tightened in 2024 to exclude unlicensed subbies entirely from SOPA, requiring NSW Fair Trading or contract pathways instead.

Cross-state notable points:

State	Notable feature
NSW	Owner-occupier excluded from SOPA; subbie must use HBA path; unlicensed subbies excluded since 20 Aug 2024
QLD	BIF Act adds Project Trust for projects over $1M private / $10M public; trust funds protect subbie payments
VIC	”Excluded amounts” restriction repealed effective 15 April 2026; previously excluded set-offs, damages, etc. from adjudication
WA	West Coast model; less aggressive default; less commonly used
NT	West Coast model

Builder takeaway:

Treat every payment claim as serious; lodge a payment schedule within the SOPA window every time.
If you’ve defaulted on a payment schedule, expect a deemed admission and an adjudication application landing fast.
Document the project scope, variations, and deductions in real time; you have only the payment schedule reasons to rely on later.
For project trusts (QLD) on large jobs, maintain the trust account discipline; non-compliance is a regulator offence.
Brief the office staff on SOPA timings; missing a 10 BD deadline is the #1 SOPA defect.

Also known as: Security of Payment Act; SoPA; BIF Act (QLD); Construction Contracts Act (WA, NT).

Category: Contracts & commercial.

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