How a Plintha Analysis Works: Every Number Computed or Flagged

The method, in brief

• —Finance engine: every dollar figure — stamp duty, cash flow, tax position, depreciation, 10-year equity — comes from a deterministic finance engine in code, not from the AI. Given the same facts, it returns the same numbers every time.
• —Data sources: the listing details you provide, verified state and territory revenue office duty and land-tax rates, ABS Census and population data, ABS building approvals, and market benchmarks for yield and vacancy — each figure in the report shows where it came from.
• —Honesty principle: every number is tagged computed, [ESTIMATE], or [ASSUMED]. Where a figure can't be responsibly modelled — entity tax for an SMSF, trust or company, for example — Plintha says so instead of guessing.
• —Decision-support, not advice: Plintha produces general property information and analysis, not personal financial, tax, credit or legal advice, and it isn't a recommendation to buy, sell or hold. Confirm decisions with a licensed professional.

Step one: paste a listing, get a full financial model

The starting point is a property listing. Plintha's finance engine builds the acquisition and holding model from it: stamp duty computed exactly for all eight states and territories and verified against each revenue office, land tax worked through the actual bracket maths, loan costs, and ongoing cash flow.

The model runs on sensible, visible defaults — an 80% LVR, 6.5% p.a. interest on an interest-only loan over a 30-year term, property management at 8% of rent, a vacancy allowance of 3% of rent, and maintenance at 0.7% of the purchase price per year. Every one of these is overridable in Advanced settings. If you push the LVR above 80%, the model adds lenders mortgage insurance.

The 2026–27 Budget changed the tax maths — Plintha classifies for it

Since the 2026–27 Federal Budget, the tax treatment of an investment property depends on what it is and when you bought it. Rental losses are deductible against salary only for new builds purchased or contracted from 12 May 2026; properties held or contracted before that date are grandfathered under the old rules; and established properties bought after that date have their losses quarantined — carried forward against future rental profits or the eventual capital gain, not your salary.

Plintha classifies every property as grandfathered, new build, or established post-budget, and the classification changes the tax modelling. Depreciation is modelled with awareness of the building's physical age across both Division 40 plant and equipment and Division 43 capital works — relevant because since 2017, deductions on second-hand residential plant have been restricted: broadly, only new plant qualifies for subsequent owners.

The honesty rule: computed, [ESTIMATE], or [ASSUMED]

Every number in a Plintha report carries one of three provenance flags. Computed means the engine derived it exactly — stamp duty is the clearest example. [ESTIMATE] means an assumption was needed and it is shown: when land value is unknown, for instance, Plintha estimates it at roughly 60% of the price for a house and flags it. [ASSUMED] means a default was used, and you can override it.

This rule extends to what Plintha refuses to model. For SMSF, company or trust ownership, Plintha deliberately does not model entity income tax — it shows the pre-tax position and refers the entity tax question to your accountant. A tool that guessed at trust tax after the 30% minimum on distributions arrives from 1 July 2028 would be doing you a disservice.

Stress testing and conflict checks come standard

Every analysis includes a stress test: interest rates 2% higher, an extended vacancy period, and the interest-only period expiring and flipping the loan to principal-and-interest — the moment repayments jump. A deal that only works under today's conditions is a different proposition from one that survives all three.

Plintha also runs a buyer's-agent conflict check. It reads who pays whom on the deal and flags the arrangement, so you know whose interests the advice around a property actually serves.

What it costs

The free tier gives you one analysis per month with no card required. Beyond that, credits are priced at 1 for $89, 3 for $229, 5 for $349, or 15 for $899, and stay valid for 12 months. Reports are kept for 90 days in your Deal Vault.

Common questions