Custom Software Development Cost in Australia

Why do published price ranges for custom software disagree so much?

Most price ranges in vendor articles cite no data and reflect the author’s own project mix.

The deeper problem is estimation itself. Construx’s summary of estimation research shows that an estimate made at the initial concept stage can be inaccurate by a factor of four on the high side or the low side, a sixteen-fold spread. The range narrows as the product definition, requirements and interface design are completed. A figure given before that work exists is a guess about scope nobody has written down.

Overruns compound the spread. McKinsey and the University of Oxford’s BT Centre for Major Programme Management studied more than 5,400 IT projects. Large projects, defined by initial price tags above $15 million, ran 45% over budget and 7% over time while delivering 56% less value than predicted, and software projects carried the highest overrun risk. The study covered large projects and dates from 2012, so the percentages indicate direction only. Software budgets should plan for overrun.

What drives the cost of custom software?

The table lists the drivers that separate a small internal tool from a regulated platform. Each one changes effort, the day rate, or both.

How do you calculate a realistic budget?

Use one formula and fill it with numbers you can defend:

Budget = Σ (role × days × day rate) + non-labour costs + contingency

Effort comes from a scoped backlog. Brainstack plans four to eight weeks for a minimum viable product and three to six months for a full-featured application; treat that as one vendor’s view.

For the rate side, start with what the same team would cost you to employ. Robert Half’s 2026 Australian technology salary guide, based on its placement data, gives these medians. Superannuation guarantee is 12% for 2025–26 and 2026–27.

That figure excludes recruitment fees, payroll tax, workers’ compensation insurance, equipment, software licences and management time. It also excludes the wait. Sydney recruiter Big Wave Digital reports six to ten weeks from brief to signed offer for a mid-to-senior engineer, plus two to four weeks’ notice. That is a recruiter’s operating estimate. It still means a team hired from scratch starts roughly a quarter after the budget is approved.

Convert salary to a day cost. Assume 260 weekdays, less four weeks’ annual leave (20 days) and ten days’ personal leave under the National Employment Standards, and ten weekday public holidays (the number varies by state and year). That leaves 220 available days. A median senior developer then costs A$764 per available day in salary and super alone. The five-person team averages A$692 per person-day.

For a vendor, five people for six months at 20 billable days a month is 600 person-days. The table shows how far the day rate moves the total. Illustrative day rates for the arithmetic only. They are not Brainstack’s rates and not market data. Replace them with the rates in the quotes you hold.

A vendor’s day rate also carries its own on-costs, bench time and margin. An onshore quote well below the in-house reference deserves a direct question about seniority or excluded scope.

Add non-labour costs: cloud hosting, third-party licences and APIs, penetration testing, accessibility audit and legal review. Then set contingency against the post-discovery estimate, because a short paid discovery phase moves the estimate towards the narrow end of the range.

Fixed price, time and materials or a dedicated team: which costs less?

The cheapest model depends on scope stability and how much delivery management you can supply.

The choice between a dedicated team and staff augmentation comes down to who directs the work day to day. Our comparison of the two models sets out the trade-offs.

Which Australian rules add cost to a custom build?

Offshore access to personal information. Under APP 8, an organisation discloses personal information when it makes it accessible outside the entity and releases it from its effective control, and it stays accountable for the overseas recipient’s handling (section 16C of the Privacy Act). An offshore engineer who restores a production snapshot to reproduce a bug has usually received a disclosure. Masked test data, logged access and contracts that bind subcontractors belong in the quote.

Customers regulated by APRA. If you sell to banks, insurers or super funds, their standards reach you. CPS 234 requires them to evaluate a third party’s information security controls and confirm those controls are tested. CPS 230, in force since 1 July 2025 and remade in April 2026 with the current version commencing 1 July 2026, treats core technology services as material by default, requires contracts that give APRA access to data, and requires notice to APRA before a material offshoring arrangement. Budget for security questionnaires, penetration-test evidence and longer contract negotiation.

Privacy exposure beyond the regulator. A statutory tort for serious invasions of privacy commenced on 10 June 2025. From 10 December 2026, organisations using a computer program to make decisions that could significantly affect an individual’s rights or interests must describe those decisions in their privacy policy. That logic needs documentation.

Hosting. AWS Sydney (ap-southeast-2) has operated since November 2012 and AWS Melbourne (ap-southeast-4) since 23 January 2023. Data residency is set by the region your own cloud account uses. The vendor’s location decides who can reach that data.

Why do two quotes differ, and what should you check before accepting one?

Quotes for the same brief differ because vendors assume different inclusions, team shapes, risk allocation and run costs, and because some quote before discovery. One quote includes QA automation, deployment and hypercare; another ends at code handover. Make every vendor price the same line items.

Quote checklist

• Inclusions itemised: QA automation, security testing, deployment, documentation, hypercare
• Named roles, seniority and allocation for every line
• Day or monthly rates per role, with the currency stated
• Written assumptions and a change process
• Discovery outputs (backlog, architecture, estimate) before the build price is fixed
• A 12-month run-cost estimate
• The team roster shown in IST and AEST/AEDT
• Where production data lives, who can reach it from which country, and the APP 8 contract terms
• IP assignment in the contract, code in your repository and infrastructure in your account

When is custom software the wrong answer?

When a product already fits. If an off-the-shelf product covers the workflow with configuration, license it. Custom software earns its cost when the workflow is non-standard, the integrations are unusually deep or the data model is genuinely yours.

When nobody owns the outcome. If you cannot name the one internal person accountable for what gets built, external capacity will produce code nobody has agreed is right. Symptoms: priorities change weekly and demos end without decisions. The fix is free: appoint the owner before you request quotes.

When there is no run budget. Software without funding for patching, monitoring and support decays from the day it launches. If the run cost does not fit, reduce the scope.

What does Brainstack charge?

Brainstack quotes each engagement on request and does not publish a rate card. The minimum project is A$25,000.

Each engagement model is priced differently: outsourced builds are fixed-scope per phase with milestone invoicing, dedicated teams a monthly retainer per team, staff augmentation a monthly rate per engineer, and consulting a fixed price per deliverable. We share rate cards under NDA. Builds usually start with a paid discovery phase of one to two weeks.

Engineering runs from Delhi NCR, where Brainstack has built production software since 2016, with a Melbourne coordination office. Australian clients’ applications run in AWS Sydney in the client’s own account by default, and we do not store production data in our infrastructure. To test these numbers against your brief, book a scoping call.

Frequently asked questions