Determination (SOPA adjudication)
Determination is the SOPA adjudicator's written decision on the disputed amount. Enforceable as judgment debt; interim only, doesn't end the underlying dispute.
Ask Chalkline about this →A determination is the written decision issued by a SOPA adjudicator at the end of an adjudication, setting out the amount the respondent must pay the claimant (the “adjudicated amount”), the reasons for the decision, the date by which the amount must be paid, and the allocation of the adjudicator’s fees. The determination is interim binding on cashflow: enforceable as a court judgment debt, but the underlying contractual dispute can still be litigated separately. This is the “pay now, argue later” principle that defines security of payment legislation across Australia (verified 2026-05-16; SOPA NSW s.22 is the typical example).
Timeline (NSW):
| Step | Time limit |
|---|---|
| Adjudication response lodged (or due to be lodged) | Day 0 of determination period |
| Adjudicator’s determination issued | Within 10 business days (extendable by mutual agreement) |
| Adjudicated amount due for payment | 5 business days after determination, typically |
| If unpaid: adjudication certificate may be obtained | At expiry of payment period |
| Certificate registered in court | Becomes a judgment debt with full enforcement powers |
Total typical pathway: from payment claim to enforceable judgment in 8 to 12 weeks. This pace is the whole point of SOPA; ordinary contract litigation runs 12-24 months.
Mandatory contents of a determination (SOPA NSW s.22):
| Section | What it covers |
|---|---|
| Date | Date of determination |
| Adjudicated amount | The amount the respondent must pay, in dollars |
| Date for payment | Specific date, usually 5 BD after determination |
| Rate of interest | Per the Act, on the determined amount from due date |
| Reasons | Adjudicator’s reasoning on the disputed items |
| Costs allocation | How adjudicator’s fees are split (respondent usually, unless adjudicator orders otherwise) |
| Signature | Adjudicator’s signature; sometimes the ANA stamp |
What “interim binding” means:
| Binding aspect | What it does |
|---|---|
| Cashflow | Respondent must pay the adjudicated amount; failure triggers enforcement |
| Enforceability | Registered determination operates as a judgment debt |
| NOT final on contract | Either party may litigate the underlying dispute in court afterwards |
| NOT res judicata | Court can revisit the same dispute and reach a different conclusion |
| Recovery | If court eventually finds the claimant was overpaid, the respondent can recover the excess |
The interim nature is critical: SOPA is a cashflow protection mechanism, not a substitute for the courts. A respondent who is convinced the adjudication was wrong should pay the determination (to avoid enforcement) and then sue in court for recovery. This is the standard playbook.
Grounds for challenging a determination:
A determination cannot be appealed on the merits. Limited grounds for setting aside in the Supreme Court:
| Ground | When it applies |
|---|---|
| Jurisdictional error | Adjudicator decided matters outside the scope of SOPA jurisdiction |
| Failure to provide procedural fairness | One party not heard; clear breach of natural justice |
| No reasons given | Reasons mandate not met |
| Determination affected by bias | Adjudicator’s interest disclosed too late |
| Adjudication application out of time | Procedural defect undermines the foundation |
Successful challenges are rare in NSW; the courts have consistently upheld a narrow scope of review to preserve SOPA’s interim-binding character. Even where a determination contains errors of fact or law, the courts decline to disturb it unless the error is jurisdictional.
Cross-state variation in determination timing:
| State | Determination time after response/lodgement |
|---|---|
| NSW | 10 business days (extendable by agreement) |
| QLD | 10 business days under BIF Act |
| VIC | 10 business days |
| WA | 14 days (Construction Contracts Act) |
| NT | 14 days |
| SA, TAS, ACT | State-specific |
Common defects in adjudications (from the adjudicator’s perspective):
- Reasons skeletal or absent (vulnerability to challenge).
- Calculation errors in the adjudicated amount (rare ground to challenge if substantive).
- Failure to address a payment-schedule reason (jurisdictional risk).
- Determination issued outside the time window (challengeable).
Also known as: adjudication determination; adjudication decision; SOPA determination; written decision; the adjudication.
Category: Contracts & commercial.
Related
See also
Last updated: 2026-05-16. Verified: 2026-05-16. Quarterly review for currency.