CA ANZ Core 4: Tax (NZ) common mistakes
CA ANZ Core 4: Tax (NZ) · Understand the traps and how to avoid them.
Calculating PAYE or terminal tax by applying the personal marginal rates directly to total income without first deducting the correct tax credits, ACC earners' levy treatment, or the low-income rebate, and then reporting the unadjusted figure as the final liability.
Candidates memorise the rate thresholds but practise only on gross-income examples, so the credit-and-rebate step is never rehearsed and gets dropped under time pressure. The arithmetic looks complete, which suppresses the self-check that would otherwise catch the omission.
What to do instead
Adopt a fixed four-line working for every individual tax computation: assessable income, deductions, tax at marginal rates, then credits and rebates (including the independent earner and low-income entitlements where they apply). Rehearse the template on at least five past-style scenarios with credits before the exam so the sequence is automatic.
Treating an item as deductible or non-deductible by labelling it (for example calling a payment 'capital' or 'personal') without applying the general permission and the capital limitation to the actual facts, and without checking the nexus to income-earning activity.
The categories feel intuitive, so candidates pattern-match to a familiar example instead of working through the statutory tests. The two-limb structure of the general permission is easy to state and easy to skip when the conclusion seems obvious.
What to do instead
Write the two limbs explicitly for every deduction question: is there a nexus to deriving assessable income or carrying on a business, and does a limitation (capital, private, or specific prohibition) apply? Then check whether a specific provision overrides the general rule. Practise on borderline items such as legal fees, relocation costs, and fines.
Recognising income or claiming deductions at the date cash moves, rather than applying accrual accounting and the specific timing rules for expenditure, unexpired prepayments, and accrued income.
Cash thinking is natural and reinforced by everyday experience. Candidates also conflate the general accrual concept with the specific accrual rules for financial arrangements, so they miss both the trading-income timing tests and the spreading requirements.
What to do instead
For each timing question, ask three questions in order: is the taxpayer on accrual or cash basis, does a specific timing provision apply (prepayments, accrual rules, trading stock), and only then default to the general principle. Build a one-page timing decision tree and apply it to a fact pattern with a straddling balance date.
Valuing closing stock at cost only, or at the wrong comparative figure, and failing to compare the permitted valuation methods or apply the lower-of-cost-and-market option and the specific rules for declining or obsolete stock.
Candidates learn one method and reuse it. The requirement to compare cost with market value, and the interaction with the trading stock rules and the effect on assessable income, is a multi-step check that is rarely practised end to end.
What to do instead
Set out closing stock as a table with opening stock, purchases, closing stock under each permitted method, and the resulting gross income, then select the method that produces the correct statutory outcome. Do at least three worked examples involving write-downs and obsolete stock.
Computing a company's imputation credit account balance or dividend withholding outcomes without tracing the credit through to the shareholder, and ignoring the interaction between company tax paid, imputation credits, and the shareholder's own marginal rate.
Entity-level and shareholder-level tax are studied in separate blocks, so candidates treat the company computation as the endpoint. The integration step requires holding two tax positions in mind at once, which is harder than either alone.
What to do instead
For every entity question, complete the chain: entity taxable income, entity tax, credit attached to the distribution, shareholder gross-up, shareholder tax at marginal rates, and the residual credit or top-up. Practise with a company and a shareholder on different marginal rates so the imputation effect is visible.
Applying the look-through company regime by default to any small company, without checking the entry criteria, the loss limitation rule, or whether an election has actually been made and remains valid.
The look-through company is taught as an attractive option for small businesses, so candidates associate it with size rather than eligibility. The loss limitation rule and election mechanics are technical details that get compressed in revision.
What to do instead
Memorise a short eligibility checklist (incorporation, number of owners, type of activity, election status) and a separate loss limitation test. For any scenario question, state explicitly whether the company qualifies, whether an election exists, and how losses are limited before computing owner-level income.
Treating GST as a simple 15 percent multiplication on the invoice total, without identifying whether a supply is zero-rated, exempt, or subject to the special time-of-supply and adjustment rules, and without separating the GST component from GST-inclusive amounts correctly.
The headline rate is memorable and arithmetic is quick, so the classification step is skipped. Candidates also confuse exempt supplies with zero-rated supplies because both produce no GST on the invoice but differ in input tax entitlement.
What to do instead
Before calculating, classify the supply and state the consequence for output tax and input tax entitlement. Then compute using the correct gross-to-net or net-to-gross formula. Drill a mixed set of supplies (financial services, exported goods, residential accommodation, going concerns) and note the input tax treatment for each.
Analysing a property sale by asking only whether the taxpayer intended to resell, without working through the land taxing provisions, the bright-line test, the residential land withholding rules, and the interaction with the main home exclusion.
Intention is the intuitive test and the one most often discussed, so it crowds out the statutory tests. The bright-line rules have changed repeatedly, and candidates rely on an outdated version of the period or the exclusion conditions.
What to do instead
Use a fixed sequence for every property question: date of acquisition and disposal, applicable bright-line period at that date, main home exclusion and its limits, other land provisions (intention, dealing, development, rezoning), then withholding and return obligations. Verify the current bright-line settings from the exam-permitted legislation rather than memory.
Handling a cross-border payment by taxing it or allowing a deduction without first determining residence, source, and the applicability of a double tax agreement, and without checking whether withholding tax or a foreign investment fund or controlled foreign company rule applies.
Domestic rules are studied first and dominate practice, so the residence-and-source gateway is assumed rather than tested. Treaty relief and the foreign investment fund regime are perceived as specialist topics and are left to the end of revision.
What to do instead
Open every international question with the two gateways: is the person resident, and is the income sourced in New Zealand? Then apply the specific regime (withholding, foreign investment fund, controlled foreign company, transfer pricing) and finally any treaty relief. Practise a fact pattern involving a non-resident contractor and a resident with offshore shares.
Concluding that an arrangement is void against the Commissioner on the basis of a purposive or commercial-nonsense argument alone, without identifying the arrangement, the tax avoidance purpose or effect, and the reconstruction the Commissioner would make, and without considering the specific anti-avoidance provision first.
The general anti-avoidance provision is memorable and rhetorically satisfying, so candidates reach for it whenever a structure looks artificial. The required analytical steps, and the priority given to specific provisions, are lost in the rush to a conclusion.
What to do instead
Structure the answer: identify the arrangement, apply the specific provision first, then test the general provision by identifying the purpose or effect of the arrangement and the commercial and parliamentary contemplation. Finish by stating the reconstruction and the penalty or shortfall position. Rehearse on a scenario with a specific provision that already applies.