Selling a house with a septic system: get the paperwork ready before the buyers do

Written by Septic Help editors Last reviewed 20 Aug 2026

Buyers of unsewered properties are better informed than they were ten years ago. Their conveyancer will ask about the wastewater system, their inspector will want the lids off, and a gap in your paperwork reads as a problem — even when the system is fine. A few weeks of preparation before listing turns the septic from a negotiation lever against you into a non-event.

The paperwork buyers (and their conveyancers) ask for

Assemble one folder, digital or paper, holding:

• The council approval to install and, where your state uses one, the current approval to operate or certificate to use;
• The system design or site plan showing tank, land application area and any reserve area;
• Pump-out receipts — ideally showing a 3–5 year rhythm for a conventional tank;
• Service reports and the current service contract for an AWTS (quarterly, in most states — buyers of aerated systems know to ask);
• Records of any repairs or alterations, with the council approval that covered them;
• The manufacturer, model and installation date of the tank or treatment plant.

A complete folder answers 90% of buyer questions before they're asked. A missing approval, on the other hand, is the kind of thing that surfaces in the buyer's council search anyway — better you find it first.

Get your council records straight

Ring your council's environmental health team and ask what their file shows for your system. Three things to confirm: the approval matches the system actually installed (including any bathroom you've added since), any operating approval is current, and there are no outstanding notices. In NSW, where councils administer on-site sewage management under section 68 of the Local Government Act 1993, operating approvals run on renewal cycles — Wingecarribee Shire Council, for example, issues them for 2, 3 or 5 years by risk level, and its buying-and-selling fact sheet tells owners to lodge an application to operate promptly to avoid delaying the transaction. A lapsed approval is a fixable problem; discovering it two weeks before settlement is not the time to fix it. The state approvals guides cover who regulates what in your state.

What's worth fixing before listing

Walk your own land application area the way a buyer's inspector will: boggy ground, smells, surfacing effluent and lush green stripes are the classic signs of failure, and they photograph badly. Cheap, high-return jobs before listing:

• Pump out the tank if it's been more than 3–4 years ($300–$600) — it also lets an inspector see the tank properly and shows you've maintained it;
• Fix lids, risers and covers — cracked or unsecured lids are a safety flag every inspector notes;
• Service the AWTS and bring the service log up to date;
• Mow and mark the tank and trench area so inspections don't start with "we couldn't find it".

Bigger calls — failing trenches, a dead pump — are a judgement between fixing before sale and adjusting the price. As a rule, fix what makes the system compliant; negotiate what's merely old. A quote in hand from a local contractor (see the directory, or get quotes) beats a buyer's inflated guess at the cost of the work.

Disclosure rules by state

What you must tell buyers varies more than most agents realise:

• Victoria — the section 32 vendor statement under the Sale of Land Act 1962 must disclose that the property is not connected to mains sewerage. Get it wrong and the purchaser may be able to rescind before settlement; conveyancing case notes record exactly that happening where the statement missed the septic. Include the septic permit and council records with the statement.
• Queensland — since 1 August 2025, sellers must give a disclosure statement (Form 2) with prescribed certificates before the buyer signs. It covers title, zoning and notices — including any council notices over the system — but not the system's condition or structural soundness, which stays buyer-beware.
• NSW — prescribed vendor disclosure focuses on planning certificates and title; there's no general duty to volunteer the septic's health. But many councils expect the operating approval to be dealt with at sale, and the buyer's council search will find your file, so accuracy beats silence.
• Other states — WA, SA and Tasmania have no septic-specific vendor disclosure, though the usual rules against misleading answers apply everywhere: if a buyer asks whether the system has failed and you know it has, say so.

At and after settlement

Hand over the folder: approvals, plans, service history, and the name of your service contractor — for an AWTS, ask whether the service contract can transfer, since a buyer stepping into an existing contract is one less objection. In NSW, remind the buyer (through your conveyancer) that many councils require them to apply for the approval to operate within about three months of purchase; it costs you nothing and starts the relationship clean.