Adjudication response (SOPA)
Adjudication response is the respondent's written reply under SOPA NSW s.20. Lodged within 5 business days; can only rely on reasons already in the payment schedule.
Ask Chalkline about this →An adjudication response under the Security of Payment Act 1999 (NSW), section 20, is the written response that a respondent may lodge with the adjudicator after receiving an adjudication application from a claimant. The response is the respondent’s one formal opportunity to argue against the claim before the adjudicator makes a binding determination. It is constrained by a hard rule: the response can only rely on reasons for withholding payment that were already stated in the respondent’s payment schedule. New reasons introduced for the first time in the response are excluded (verified 2026-05-16; NSW SOPA s.20(2B)).
Timeline (NSW):
| Step | Time limit |
|---|---|
| Adjudication application lodged by claimant | (Starts the clock) |
| Adjudicator acceptance | 4 business days typical |
| Respondent receives notice | Day of acceptance |
| Adjudication response lodged | The later of: 5 business days after receiving the application, OR 2 business days after the adjudicator’s acceptance notice |
| Adjudicator’s determination | Within 10 business days from response (extendable by mutual agreement) |
In practice, the respondent has about 5-7 business days from receiving the adjudication application to prepare and lodge the response. This is short for non-trivial disputes. Respondents who treat payment claims casually and fail to issue payment schedules within time, then face an adjudication, find themselves with no response window at all (if no payment schedule was issued, the respondent cannot lodge a response, and the adjudication proceeds on the claimant’s evidence alone).
The “no new reasons” rule:
| Stage of the dispute | What the respondent can argue |
|---|---|
| Payment claim received | (Internal review) |
| Payment schedule lodged | Whatever reasons the respondent identifies and includes |
| Adjudication application received | (The respondent must respond using ONLY the reasons from the payment schedule) |
| Adjudication response lodged | Only reasons already in the payment schedule, with supporting evidence |
| Adjudication determination | (Binding outcome) |
If the respondent’s payment schedule said “we dispute the amount because work item 3 is incomplete” but the response says “we dispute the amount because work item 3 is incomplete AND there is a defect AND a variation isn’t agreed”, the defect and variation arguments are excluded by s.20(2B). The adjudicator can only weigh the reasons originally raised.
What goes in the adjudication response:
- Cover identifying the application reference, claimant, respondent, contract.
- Statement of reasons for the disputed amount (must mirror the payment schedule).
- Supporting evidence: contract documents, correspondence, expert reports, photographs.
- Submission on amount: what the respondent says the proper amount is, with calculation.
- Submission on interest (where claimed).
- Submission on costs (where each party seeks costs).
- Schedule of authorities if legal arguments are made.
Lodging the response:
The response is lodged with the adjudicator (not with the claimant), through the same Authorised Nominating Authority (ANA) that processed the application. The claimant is served a copy by the adjudicator. The adjudicator then has typically 10 business days to issue the determination.
Common defects in adjudication responses:
- New reasons introduced: most common error. Adjudicator excludes anything not already in the payment schedule.
- Late lodgement: missed the 5-business-day window. Adjudicator may proceed without the response.
- Insufficient evidence: a bare assertion is not evidence. Photos, dated correspondence, contractor statements, expert reports help.
- Conflating “we don’t agree” with “we have a reason”: a respondent who simply disputes without articulating why is not making a useful response.
- Failure to address counterclaim or set-off: if the respondent intends to claim back damages or set-off, those are typically NOT available through SOPA adjudication; they require separate proceedings.
Cross-state variation:
| State | Adjudication response time |
|---|---|
| NSW | 5 business days after receiving the application (or 2 BD after acceptance, later) |
| QLD | 10 business days (BIF Act); also constrained to existing payment schedule reasons |
| VIC | 5 business days; constrained |
| WA | 14 days (Construction Contracts Act); broader response scope |
| NT | 14 days; similar to WA |
| SA, TAS, ACT | State-specific; check the local Act |
Also known as: s.20 response (NSW); respondent’s adjudication submission; counter-submission; respondent’s case.
Category: Contracts & commercial.
Related
See also
Last updated: 2026-05-16. Verified: 2026-05-16. Quarterly review for currency.