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Southern Cortex · Melbourne

Software that thinks the way finance works.

AI-powered products and custom solutions for business. Cortex Ledger is available now, from A$100 a month.

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  • Melbourne, Australia
  • AUD pricing
  • 10-day free trial
  • Unlimited users
Our first product

Cortex Ledger. One ledger, every dollar, fully explained.

It bills, collects, buys, stocks, closes the books and explains every figure. Built in Australia for businesses that have outgrown spreadsheets.

  • Eight modules, one ledgerBilling, collections, finance and GST, purchasing, inventory, AI, revenue assurance and profitability.
  • Approvals and roles built in17 job roles with separation of duties, and an audit log of every change.
  • An assistant that asks firstCortex answers in plain words, shows its working and changes nothing without your say.
Explore Cortex LedgerSee pricing

Built from the Cortex Ledger demo company.

Custom solutions

Your problem is particular. Your software can be too.

Alongside our own products, we design and build custom solutions for the crucial problems off-the-shelf software leaves unsolved, using AI where it takes real work off your people.

See how we workTell us your problem

  • Work that lives in a spreadsheet

    A critical step runs on a file that one person understands, and everyone hopes they never go on leave.

  • Approvals that stall

    Requests wait in inboxes with no clear owner, and nobody can say where a thing is.

  • Numbers nobody fully trusts

    Reports take days to check and still draw questions in the meeting.

How we build

Three ideas behind everything we make.

  1. Clarity

    Every number explained, in plain words.

    The dashboard and the daily brief say what changed, what is overdue and who owes the most, in sentences you can read in five seconds.

  2. Control

    The right person approves the right thing.

    Roles keep the person who enters a document from approving it, and every important change is written to an audit log.

  3. Courage to rethink

    We rebuild what others accept as normal.

    Three-way matching holds a vendor bill when its price differs from the order, instead of leaving it to a spreadsheet.

Built in Australia

Made for the way Australian businesses run.

Australian dollars, GST and ABNs are in the product from the first invoice.

  1. Australian dollars

    Amounts are in AUD. When an invoice is in another currency, the exchange rate is recorded on it.

    Fig. 1 Foreign-currency invoice
    Foreign-currency invoiceUSD
    Line 1USD 100.00
    Rate recordedUSD/AUD 1.48120027 Oct 2026
    In Australian dollarsA$148.12

    Worked example using a recorded rate from the demo company.

  2. GST on every line

    GST is worked out line by line, then reported in the ledger next to the income statement and balance sheet.

    Fig. 2 Draft invoice
    Draft invoiceGST on every line
    LineAmountGST
    Line 1$1,200.00$120.00
    Subtotal$1,200.00
    GST$120.00
    Total (AUD)$1,320.00

    Reported in the ledger with the income statement and balance sheet.

  3. ABN and terms on every customer

    Each customer carries an ABN, payment terms, a credit limit, addresses and statements.

    Fig. 3 Customer record
    H
    Harbour Energy Pty LtdCustomer
    ABN53 102 202 302
    CurrencyAUD · 1.0000
    • Terms
    • Credit limit
    • Addresses
    • Statements

  4. A month-end that closes

    A close workbench lists what is still open before a period can be closed. It never closes one for you.

    Fig. 4 Period close workbench
    Period close workbenchNot ready to close
    August 20262026-08-01 to 2026-08-31
    2Critical blockers5Advisory items
    CriticalRevaluation not run37,827.43
    CriticalLedger check—

    It lists what is open. It never closes a period or posts anything.

Control you can see.

Cortex Ledger is built so a person stays in charge of anything that matters, with AI doing the reading and the matching.

  • Approvals before anything goes out

    Invoices, orders and credit notes wait for a decision.

  • The maker cannot be the approver

    The person who enters a document cannot approve it.

  • A full audit log

    Who did what, and when.

  • Closed periods stay closed

    Once a period is closed, the numbers in it stop moving.

How we keep you in control How our AI works

Questions

Questions people ask us.

What does Southern Cortex do?

We are an Australian software company. We build AI-powered solutions for business, custom products and solutions for crucial business problems, and our own products, starting with Cortex Ledger.

What is Cortex Ledger?

One system that bills, collects, buys, stocks, closes the books and explains every figure, with an AI finance assistant. It is available now, from A$100 a month. GST is included in the price.

Do you build custom software?

Yes. We start from the problem that costs your business most, then build in small working steps. Tell us the problem on the Custom solutions page.

Is my data safe with an AI?

Cortex reads only what your role may read, asks before it changes anything, and records important changes in an audit log. Security documentation is available on request.

Ready to see your business in a new light?

Book a 30-minute demo and see Cortex Ledger with your own questions.

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