Xero treats a multi-stage Defence progress claim like a normal invoice, and it isn't
Custom accounting software, or a custom layer over your existing platform, runs $40k to $95k over 3 to 6 months in Darwin. QuickBooks and Xero are excellent general ledgers and weak at construction and Defence billing. Progress claims, retentions and remote job costing don't fit their invoice model, so your finance team rebuilds the maths in spreadsheets every month.
You do Defence-support, gas-servicing or construction work that bills in progress claims with retentions held back, and Xero or QuickBooks sees only a flat invoice. Every claim, every retention release, every variation gets reconstructed in a spreadsheet, then keyed back in, and one tired Friday error throws out the whole job's margin. Your accounting software is a ledger, not a project-billing system, and the gap is doing real damage.
Remote job costing makes it harder. Costs for a job three hours out, fuel, allowances, sea freight, mobilisation, land in the system days late and are hard to attribute, so you don't know a remote job's true margin until well after it's done, when it's too late to fix.
The fix: accounting built for Darwin, not rented
A custom accounting layer handles progress claims, retentions and variations natively, so finance stops rebuilding them by hand. It captures remote job costs as they happen, including fuel and freight, and shows live job margins. It keeps your existing ledger for compliance and tax, adding the project-billing and job-costing intelligence QuickBooks and Xero lack.
The capability list that earns its budget
Darwin accounting: the full scope
Everything an accounting build here can cover: accounts receivable, general ledger, expense management, custom accounting software, QuickBooks integration, Xero integration and invoicing software.
What accounting costs in Darwin
| Project scope | Typical cost | Timeline |
|---|---|---|
| Progress-claim and retention layer | $40k to $60k | 3 to 4 months |
| Full job-costing and billing system | $70k to $95k | 4 to 6 months |
| Costing module over existing ledger | $30k to $50k | 2 to 4 months |
How long it takes, phase by phase
Exactly what you get
You get the project-billing and job-costing brain QuickBooks and Xero never had. Progress claims, retentions and variations are handled natively, remote job costs are captured as they happen, and you see live margins while you can still act on them. Your existing ledger stays for tax and compliance, and the new layer connects to your ERP and project management software.
How to choose a developer in Darwin
Choose a developer fluent in construction and Defence billing, not just general accounting. Ask how they model a retention release and a contract variation. Confirm they'll layer on your existing ledger rather than replacing it, and ask how they capture a remote job's fuel and freight against the right cost code. Financial logic must be exact, so probe how they test it.
- Native progress-claim, retention and variation handling
- Live job costing that captures remote costs as they occur
- Accurate job margins during the work, not months later
- Retention tracking and release scheduling done automatically
- Keeps your existing ledger and integrates with ERP and project tools
- Financial logic must be exact, which raises testing and cost
- You're adding a system to maintain alongside your ledger
- Tax and compliance still belong in your core accounting platform
- A simple invoicing business won't need this over Xero
- !They treat a progress claim as an invoice; ask how retentions are tracked
- !No remote-cost capture; ask how fuel and freight hit the right job
- !They want to replace your ledger; ask why not layer on top
- !No live margin reporting; ask when you'd actually see job profit
- !Weak on financial accuracy; ask how they test the maths
Teams investing in accounting in Darwin usually scope it next to warehouse management, field service management, erp, since these systems share data and budgets.
Rohan advises mid-market and enterprise teams on ERP, CRM and custom software, and has led delivery on dozens of business-software builds.
Writes for Digital Heroes, shipping business software for 2,000+ brands across 55+ countries since 2017.
Frequently asked questions
Why can't Xero or QuickBooks handle progress claims?
They're general ledgers built around standard invoices. Progress claims, retentions and variations are a project-billing model they don't represent, which is why finance teams rebuild them in spreadsheets.
Do we have to replace our existing accounting platform?
No, and usually you shouldn't. A custom layer adds progress-claim handling and live job costing while your ledger keeps doing tax and compliance, with the two integrated.
How does it capture remote job costs?
By recording fuel, freight, allowances and mobilisation against the right job as they occur, so you see a remote job's true margin during the work rather than months after.
Can it manage retentions automatically?
Yes. It tracks retention amounts held and schedules releases, so you stop missing claims and stop rebuilding the maths every month.