The most expensive tax mistakes Australian business owners make are rarely made during the life of the business. They are made at the very beginning, baked into a structure that looks fine for fifteen years — and then explodes the day the owner tries to sell. Most of these mistakes are fixable. None of them are fixable in the six months before settlement.

This guide from Trinity Accounting Practice covers the five structural tax mistakes we see most often when a buyer’s due-diligence team starts looking at a Sydney SME, and what to do about them now — whether your exit is two years away or ten.

Why structures that work for 15 years fail at exit

A typical SME tax structure is optimised for one thing: this year’s compliance bill. The entity that pays the least tax each year is the one most owners settle into. The tests that matter at exit — Maximum Net Asset Value, active asset ratios, holding period requirements — never come up in a normal annual review because they do not apply until the day the Letter of Intent is signed.

The result is predictable. A buyer’s accountants and lawyers go through the structure, the intercompany loans and the cost-base records, and the CGT concessions the owner was relying on for a tax-free exit either evaporate, are restricted, or are quietly priced into a discounted offer.

Time bomb 1 — The Maximum Net Asset Value (MNAV) trap

The Small Business CGT Concessions are some of the most generous tax provisions in Australian law — capable of producing a near-zero tax outcome on multimillion-dollar sales. To qualify, your Maximum Net Asset Value (your assets plus those of “affiliates” and “connected entities”) must be under $6 million immediately before the CGT event.

What most owners miss: that $6 million includes assets they do not directly own. A spouse’s investment portfolio. A commercial property in a separate family trust. Sometimes superannuation balances. Affiliates of business partners. Connected entities under common control.

The owner who believes the business is worth $4 million is shocked at due diligence when the buyer’s advisers map the connected entities and the aggregated MNAV comes in at $6.4 million. The concessions vanish. The tax bill jumps from near zero to 23.5% or more.

Time bomb 2 — Active business assets stuck inside a company

When the business is genuinely successful, the buyer often prefers an asset sale rather than a share sale. They get a step-up in cost base for depreciation, and they avoid inheriting historical liabilities.

The problem: a company does not receive the 50% CGT discount on asset sales (and from 1 July 2027, that discount is being replaced by indexation in any event for individuals and trusts). When the company sells its assets, it pays company tax. To get the proceeds into the owner’s personal hands, a second layer of tax applies on the distribution.

Had those same assets been held through a trust structure, capital gains could have been streamed to beneficiaries with the 50% discount intact (for transactions before 1 July 2027) or the new indexation framework (after). The structural cost of getting this wrong can run into hundreds of thousands of dollars on a meaningful sale.

Time bomb 3 — Division 7A and unpaid present entitlements

Over the years, many SMEs use a “bucket company” beneficiary to manage marginal rates. The trust distributes profits to the company on paper, but the cash stays in the trust to fund operations. The result is an Unpaid Present Entitlement (UPE) owed by the trust to the company.

If those UPEs are not properly documented as Division 7A complying loans (s109N — fixed term, benchmark interest, minimum yearly repayments), they sit on the balance sheet as a ticking compliance issue. A sophisticated buyer will require them cleared before settlement — which often means a large cash repayment from the trust, or worse, a deemed unfranked dividend in the year of sale.

The post-Bendel ATO position has tightened further: where the trust has used the funds and there is no documented sub-trust or complying loan, the ATO can treat the UPE as a Division 7A loan retrospectively. The clean-up is rarely a one-month job. It typically takes 12–24 months to do properly.

Time bomb 4 — Failing the active asset test

Access to the Small Business CGT Concessions also depends on the active asset test: at least 80% of the entity’s assets (by value) must be used actively in the business.

The problem with successful SMEs is “lazy” cash. Retained earnings sitting in term deposits. A share portfolio that was acquired three years ago when there was surplus capital. An unrelated investment property held inside the trading entity. The test is binary — if passive assets exceed 20%, the entire entity fails the test, and the concessions are gone.

This is one of the more tragic mistakes we see. The owner has “done well” — there is genuine cash in the business — and that very success has disqualified them from the most valuable tax concession they were counting on.

Time bomb 5 — Poor cost-base documentation

The business has been operating for 18 years. There have been improvements, acquisitions, fit-outs, equipment upgrades. The records are scattered, partly in old filing cabinets, partly in a shoebox, partly in a previous accountant’s archive that may no longer exist.

Without defensible records, the cost base is understated. The capital gain is overstated. The owner pays tax on “gains” that are not gains, simply because the substantiation is not there.

The fix is operational, not structural — but it takes time. Capital expenditure logs, improvement records, dates of acquisition, and incidental cost documentation should be reconstructed and filed properly well in advance of any sale process. We typically put this in place 24–36 months before a planned exit.

Share sale vs asset sale — and why the structure forces the answer

Buyers and sellers have opposing tax interests. Buyers want an asset sale: cost base step-up for depreciation, no inherited unknown liabilities, the ability to cherry-pick. Sellers want a share sale: one CGT event with concession access and a single layer of tax.

If your structure does not allow a tax-efficient share sale, you lose negotiating leverage. A sophisticated buyer’s adviser will identify this, model your after-tax position, and use it to discount the offer. The structural flaw that sat unaddressed for fifteen years becomes a direct deduction from your sale proceeds — sometimes 5–10% of the headline number.

The state, GST and cross-border layers most owners miss

Transfer duty and landholder duty — asset sales may trigger stamp duty on land, equipment or goodwill in NSW, Victoria and other states. Landholder duty applies where the entity holds significant land. Rates vary but typically add 5–6% to transaction costs.
GST going concern exemption — strict eligibility rules. If the going concern test fails, 10% GST applies to asset values. We see this overlooked until contract drafting.
Foreign resident withholding — overseas buyers face additional withholding obligations on certain property and indirect-interest transactions.
Cross-border IP and transfer pricing — for businesses with overseas-held IP or intercompany arrangements, additional layers of scrutiny apply.

The 12–36 month exit readiness timeline

36 months out — Strategic restructuring window. Genuine structural change is possible. Small Business Restructure Rollover provisions (Subdivision 328-G) are available. Trust deeds can be reviewed and amended. Division 7A loans and UPE balances can be cleaned up without forcing an immediate tax event.
24 months out — Eligibility positioning. Confirm the active asset test ratio. Address MNAV threshold issues by distributing or segregating non-active assets. Document the cost base thoroughly while records are still accessible.
12 months out — Transaction preparation. Model share sale vs asset sale outcomes. Prepare data room documentation. Engage transaction advisers (tax, legal, corporate finance).
6 months out — Damage control. Most structural changes are no longer effective due to holding-period requirements. Focus shifts to deal negotiation and tax indemnities.

Exit-ready checklist

MNAV calculation — map all connected entities and affiliates; confirm aggregated total is under $6 million.
Active asset test — calculate passive vs active assets; address if passive exceeds 20%.
Entity structure review — model exit scenarios under both share and asset sale.
Division 7A compliance — document all intercompany loans; clear or formalise UPE balances under s109N.
Cost base file — compile acquisition documents, improvement records, incidental costs.
CGT concession eligibility — verify all four (15-year exemption, 50% reduction, retirement exemption, rollover).
State duty exposure — identify landholder and transfer duty triggers in NSW (and other relevant states).
Deal structure modelling — compare share sale vs asset sale after-tax outcomes for the owner.

A Trinity insight from 22 years in practice

The single most common pattern we see is the owner who has built a genuinely valuable business over 20 years, has never had a structural review beyond the original setup, and now wants to sell within 18 months. By that point, three of the five time bombs above are usually in play, and the planning window has closed. The clients who exit cleanly are the ones who treat structural readiness as a 36-month exercise — not a six-month one. The cost of starting early is almost nothing. The cost of starting late is, in almost every case, six figures.

What this means for you

If exit is more than 2 years away: book a structural health check now. Almost everything can still be fixed.
If exit is 12–24 months away: focus on MNAV, active asset, and Division 7A clean-up. Restructure rollover may still be available.
If exit is under 12 months away: the focus shifts to deal structuring and tax indemnities. Earlier structural work is no longer possible.
If you have UPEs to bucket companies sitting unpaid: raise this with us immediately. The post-Bendel ATO position changes the answer.
If you have surplus cash inside the trading entity: the 80% active asset test needs urgent attention.

How Trinity can help

Trinity Accounting Practice has worked with Sydney business owners through structural change, succession, sale and exit since 2003. We run the five-time-bomb review against current client structures, document the gaps, build a 36-month fix plan, and coordinate the eventual transaction across tax, legal and corporate finance. The earlier we start, the cleaner the exit.

Book an exit-readiness review with the Trinity team →

General advice only. This article contains general information current as at May 2026 and does not constitute tax, financial or legal advice. It does not take into account your personal circumstances, objectives or needs. Before acting on any information in this article, you should consider its appropriateness to your situation and seek professional advice from Trinity Accounting Practice or another qualified adviser. Liability limited by a scheme approved under Professional Standards Legislation.