What to Say When a Client Disagrees With Their ATO Assessment

15 October 2026·5 min read

Quick answer: When a client is adamant the ATO has got their assessment wrong, separate the emotion from the facts first — let them vent for a minute, then find out exactly what changed and why. Explain, in general terms, that there’s a formal objection process for genuine disagreements, but be honest that it exists for cases with a real basis, not simply because something feels unfair. Be supportive without promising an outcome you can’t control. ✨

Nobody calls their accountant calmly to say “I disagree with my assessment.” It usually comes in hot — a notice arrives, the number’s different to what the client expected, and the first instinct is that something’s gone wrong. How that call goes in the first few minutes decides whether the client feels heard and informed, or hangs up more frustrated than when they called, convinced nobody’s on their side. 💖

What most accounting firms get wrong

Two common missteps sit at opposite ends. Some firms, wanting to keep the client happy, agree too readily that “yeah, that does look wrong,” before working out what happened — setting an expectation that’s hard to walk back if the assessment turns out correct. Others move straight into a dry, technical explanation of process without acknowledging the frustration, which can read as dismissive even when the advice is sound.

What actually works is sequencing: acknowledge the frustration first, as a genuine, separate step, then move into the facts. Skipping straight to either end — pure sympathy or pure process — leaves the client feeling only half addressed.

Please note: general information, not tax advice — check current official guidance before relying on it.

The Assessment Dispute Script

1. Validate without conceding: “I get why that’s frustrating, especially when the number’s different to what you expected. Let’s work out exactly what’s changed before we decide what to do about it.”

2. Get the full picture: “Can you send me the notice, and let’s compare it line by line against what we lodged — I want to see exactly where the difference is coming from.”

3. Explain the process in general terms: “If, once we’ve looked at it properly, there’s a genuine basis to disagree, there’s a formal process for raising that — it’s called an objection, and there are time limits on when it can be lodged, so let’s not sit on this too long either way.”

4. Set honest expectations early: “I want to be upfront: not every objection is successful, and I can’t promise an outcome before we’ve actually reviewed the detail. What I can promise is a clear view on whether it’s worth pursuing.”

5. Agree next steps and cost before proceeding — confirm whether a review is included in existing fees or billed separately, and roughly how long it’ll take to get a view.

Sole trader, disallowed deduction: A sole trader was adamant a deduction they’d always claimed had been wrongly knocked back. The notice, read line by line, showed the ATO had queried a substantiation issue, not rejected the deduction outright — reframing the conversation from “the ATO is wrong” to “we need better records.”

Business owner, GST adjustment: A business owner rang furious about a GST adjustment that didn’t match their own calculations. It turned out to be a timing difference between two BAS periods, not an error on either side — once laid out clearly, the frustration dropped, even though the dollar figure didn’t change.

PAYG client, after an earlier amendment: A client disputed a PAYG calculation that had shifted because of an amendment lodged months earlier, which they’d forgotten entirely. Being honest this was a flow-on effect of their own earlier change — not a fresh ATO error — was harder in the moment, but far more useful than letting the client stay convinced something new had gone wrong.

How the objection process generally works

Review the assessment against what was actually lodged, to confirm there’s a genuine discrepancy worth pursuing.
Identify the specific basis for disagreement — an objection generally needs a clear reason, not just a sense that the outcome feels unfair.
Check the relevant time limits, which vary by assessment type and entity.
Prepare and lodge the objection with supporting information, updating the client periodically rather than going quiet until there’s a decision.

💡 Worth saying plainly, early: a formal objection is not the same thing as a complaint, and it’s not guaranteed to succeed just because a client feels strongly about it. Clients generally respond better to that honesty upfront than to false reassurance followed by a disappointing result later.

Mistakes to avoid

Agreeing the assessment “looks wrong” before actually comparing it to what was lodged.
Launching into technical process explanations before acknowledging the client’s frustration.
Promising a successful outcome to keep a client calm in the moment.
Going quiet during a long review period, leaving the client to assume nothing’s happening.

Frequently asked questions

Do most client-initiated objections actually succeed?

It genuinely varies case by case, and it’s worth being honest that disagreeing with an outcome isn’t the same as having a strong case to overturn it — some objections succeed, some don’t, and a proper review is the only way to know which situation you’re in.

How do you keep a client calm during a long review or waiting period?

Regular, brief updates — even just “still waiting, nothing new to report” — go a long way. Clients get more frustrated by silence than by a genuinely long process.

What if, after review, the client is still convinced the ATO is wrong but the facts don’t support it?

One of the harder conversations in practice, worth being direct rather than avoiding it — explaining what the review found, and being honest that proceeding without a solid basis is unlikely to change the outcome, respects the client more than going along with something unlikely to succeed.

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Written by

Kate, founder of Chronically Online

I help Gold Coast and Brisbane businesses grow with branding, websites and marketing that actually works.

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