Common Mistakes Under the Security of Payment Act and How to Avoid Them

The Security of Payment Act (SOPA) is one of the most powerful tools for protecting cash flow in construction. But it’s also unforgiving. One wrong move—missed deadlines, poorly drafted claims, or service slip-ups—can wipe out your entitlements.

At Riakos Consulting, we see the same mistakes over and over. Here are the eight that cause the most damage—and how to avoid them.

Missing Strict Deadlines

SOPA’s timeframes are carved in stone. Submit late and your claim or response is worthless.

Courts have made it crystal clear: a payment schedule served even three days late is invalid. That means the respondent may lose their right to defend, and the claimant walks away with the full amount.

How to avoid it: Use a compliance calendar with automated reminders. Tie it to your project milestones so nothing slips through the cracks.

Poorly Drafted Claims

Too many claims fail because they don’t clearly identify the work. “Variation works” or “extras” won’t pass muster.

When claims are vague, respondents attack them as invalid—and courts agree. Itemisation, clarity, and supporting documents are essential.

How to avoid it: Break down every line item, tie it to contract provisions, and attach evidence (instructions, delivery dockets, site diaries).

Mixing Up Contract Rights and SOPA Rights

Contract terms and SOPA rights are separate. You might have a contract that says “no payment until completion,” but SOPA gives you a statutory right to progress payments.

Courts have consistently ruled that SOPA overrides restrictive contract clauses.

How to avoid it: Treat SOPA as a parallel pathway. Run your SOPA claims alongside contractual entitlements, not instead of them.

Waiting Until a Dispute Arises to Prepare

Adjudication moves fast. You can have as little as 5–10 business days to respond. If you start scrambling when the notice lands, you’re already behind.

How to avoid it: Maintain a live “dispute file” from day one. Keep notices, correspondence, variation records, and delay registers organised so you can respond immediately.

Getting Service Wrong

It doesn’t matter how strong your claim is if it’s not properly served. Serving the wrong person, sending to the wrong address, or relying on an unauthorised email can all invalidate your claim.

How to avoid it: Double-check the contract’s service provisions. Serve by multiple methods (email plus hand delivery, for example) and keep proof of service.

Misunderstanding Reference Dates

Every claim needs a valid reference date. Without one, your claim is void. Many contractors assume reference dates can be chosen freely—but they’re either fixed by the contract or default monthly under SOPA.

How to avoid it: Map out all reference dates at the start of the project. If the contract is silent, fall back on SOPA’s statutory monthly entitlement.

Claiming for Excluded Work

SOPA doesn’t cover everything. Claims for certain types of work—like mining or some domestic building work—fall outside its jurisdiction. If you lodge a claim for excluded work, it’s invalid.

How to avoid it: Review your scope before serving a claim. If part of the work is excluded, carve it out and claim separately under the contract.

Failing to Enforce Adjudication Determinations

Winning an adjudication isn’t the finish line. Determinations are only useful if you enforce them. Many claimants stop after the decision, while respondents stall or move assets.

How to avoid it: File the adjudication certificate with the court immediately. Use garnishee orders, statutory demands, or winding-up notices to secure payment quickly.

Final Word

SOPA can be a fast, effective way to get paid—but only if you play it by the rules. One missed deadline or poorly drafted claim can derail your entire case.

At Riakos Consulting, we specialise in helping subcontractors, contractors, and developers navigate SOPA with confidence—from drafting airtight claims to enforcing determinations.

If you can’t afford to get it wrong, get advice early.