Security of Payment Deadlines: Business-Day Rules by State

The Act or contract supplies three inputs for a security of payment deadline: the procedural step, the event that starts the period and the number of days. The applicable state or territory then supplies the definition of a business day or working day.

The calculator's SOPA (Construction) preset applies that jurisdiction's calendar. It does not select the statutory branch or number of days.

Identify the step and period before counting

A broad description such as "adjudication application" is not enough to choose a period. New South Wales s 17, for example, uses:

10 business days after receipt of a payment schedule where the scheduled amount is less than the claimed amount;
20 business days after the due date where a scheduled amount is not paid; and
a separate notice and second-chance process where no schedule was given and the claimed amount was not paid.

Queensland also distinguishes an application following a missing schedule from other adjudication applications. Victoria uses different periods for the three branches in s 18. The facts determine which branch applies.

The contract can also affect the period. In NSW, s 14 requires a payment schedule by the earlier of the contract's period and 10 business days after service of the claim. A preset period of 10 days would therefore be wrong when the contract requires an earlier response.

Statutory Christmas exclusions

All eight jurisdictions exclude weekends and public holidays. Their additional Christmas and New Year exclusions differ:

Jurisdiction	Term used	Extra dates not counted
New South Wales	business day	27–31 December
Queensland	business day	22 December–10 January
Western Australia	business day	22 December–10 January
Victoria	business day	22 December–10 January under the rules in force from 15 April 2026
South Australia	business day	27–31 December, plus any other declared statewide industry shutdown day
Australian Capital Territory	business day	27–31 December
Tasmania	business day	27–31 December
Northern Territory	working day	25 December–7 January

These are statutory exclusions. A construction-site shutdown or company office closure does not add another non-business day unless the governing definition gives it that effect.

South Australia's definition can also exclude another day declared as a statewide shutdown of building and construction operations. The calculator applies the five dates named in the Act. Check the current legislation for any additional declared day.

Victoria requires an explicit rule version

Victoria's 22 December to 10 January exclusion commenced on 15 April 2026. The transition provision says that most Part 3 amendments do not apply to a payment claim served before commencement, or to an adjudication application made but not determined before commencement.

The start date entered for a later procedural step may not show which version governs the matter. When Victoria is selected, Victorian SOPA rules therefore requires a choice between Current rules and Earlier transitional rules. Check s 54 of the Building and Construction Industry Security of Payment Act 2002 before making that selection.

NSW example: ten business days across Christmas

Assume a payment claim was served in New South Wales on Thursday 18 December 2025. Assume section 14's 10-business-day period applies because the contract does not set an earlier deadline.

Count	Date	Treatment
—	Thu 18 Dec	Trigger date; not counted
1	Fri 19 Dec	Business day
2–4	Mon 22–Wed 24 Dec	Business days
—	Thu 25 Dec–Thu 1 Jan	Public holidays, weekends and the 27–31 Dec statutory exclusion
5	Fri 2 Jan	Business day
6–10	Mon 5–Fri 9 Jan	Business days

The tenth business day is Friday 9 January 2026. That result follows only because s 14 applies, service is effective on 18 December and the contract does not require an earlier payment schedule.

The trigger date comes from the source

Different provisions run from different events. These can include service of a payment claim, receipt of a payment schedule, the payment due date, the end of a further response period or appointment of an adjudicator.

The date on which an email was sent is not necessarily the effective trigger. Victoria's current s 50, for example, deals with personal delivery, leaving a document at a place of business and post, and refers electronic communications to the Electronic Transactions (Victoria) Act 2000. Other jurisdictions have their own service provisions.

The calculator asks you for the effective start date. It does not guess that date from the delivery method.

Enter the verified inputs in SOPA mode

In Default Mode, select Deadline, then choose SOPA (Construction) as the Industry preset. Select the State or Territory, enter the effective start date and enter the period from the governing provision. If the project is in Victoria, choose the applicable Victorian SOPA rules version.

SOPA mode counts forward, excludes the trigger date and includes the final day. It applies weekends, public holidays and the additional statutory dates in the table, subject to the South Australian declared-day qualification.

The result can confirm the dates excluded by the selected calendar. It cannot establish whether the Act applies, whether a claim or schedule is valid, which procedural branch applies, whether the contract shortens the response period or when service legally took effect.