How to Write a Dispute Letter to Your Insurer

A dispute letter to your insurer should state your policy number, the date your claim was denied, the specific reason given for the denial, and a clear explanation of why you believe the decision is wrong. Reference your Product Disclosure Statement (PDS) and the General Insurance Code of Practice, and request a formal review under Internal Dispute Resolution (IDR).

Key takeaways

• Always reference your policy number, the denial date, and the specific reason your insurer gave for declining your claim.
• Cite relevant sections of your PDS, the Insurance Contracts Act, and the General Insurance Code of Practice.
• Address the insurer's reasoning point by point rather than writing a general statement of disagreement.
• Your insurer must respond within 30 calendar days of receiving your dispute letter.

When your insurance claim is denied or underpaid, your first instinct might be to pick up the phone and argue your case. But a well-written dispute letter is far more effective than any phone call. It creates a paper trail, forces your insurer to respond formally, and lays the groundwork for an external complaint if you need one later.

This guide walks you through how to write an Internal Dispute Resolution (IDR) letter that your insurer cannot ignore.

What is Internal Dispute Resolution?

Every general insurer in Australia is required to have an Internal Dispute Resolution process. Under ASIC Regulatory Guide 271, your insurer must acknowledge your complaint within one business day. Under paragraph 147 of the General Insurance Code of Practice they must then provide a final response within 30 calendar days, and under paragraph 146 they must keep you informed of progress at least every 10 business days.

If they fail to respond within that timeframe, or if you are unhappy with their decision, you can escalate your complaint to the Australian Financial Complaints Authority (AFCA) for an independent review. But a strong IDR letter often resolves the dispute before it ever gets that far.

Before you write: gather your evidence

Before putting pen to paper, pull together everything you need. A dispute letter built on solid evidence is vastly more persuasive than one based on frustration alone.

You will need:

• Your policy number and claim reference number
• A copy of your Product Disclosure Statement (PDS) and any supplementary documents
• The insurer's denial or decision letter, including every reason they gave
• Any supporting documents: photos, receipts, reports, trade quotes, or correspondence
• Notes from phone calls, including dates, times, and the name of the person you spoke with

How to structure your dispute letter

A structured letter that addresses each denial reason point by point is far more effective than a vague expression of disagreement. Think of it as building a case, not writing a complaint.

1. Open with the essentials

Start your letter with your full name, policy number, claim reference number, and the date. State clearly that you are lodging a formal complaint under the insurer's Internal Dispute Resolution process. This language matters because it triggers their obligations under the General Insurance Code of Practice to respond within 30 days.

2. Summarise the facts

Briefly outline what happened: when the event occurred, when you lodged your claim, and what decision the insurer made. Keep this section factual and concise. You are setting the scene, not arguing your case yet.

3. Address each denial reason individually

This is the most important part of your letter. Take each reason your insurer gave for their decision and respond to it separately. Quote the specific PDS clauses they relied on, then explain why their interpretation is incorrect or why the exclusion does not apply to your circumstances.

For example, if your insurer denied a storm damage claim by citing a maintenance exclusion, you might point to the specific wording of that exclusion in your PDS, then provide evidence (such as a building inspection report) showing the property was properly maintained.

Where relevant, reference the Insurance Contracts Act 1984. Section 54, which limits an insurer's ability to refuse a claim based on actions or omissions that did not cause the loss, is particularly useful. Section 13 requires insurers to act with utmost good faith, which means they must consider your claim fairly and not rely on technicalities to avoid paying.

4. Attach your supporting evidence

List every document you are attaching and explain briefly what each one demonstrates. Make it easy for the person reviewing your dispute to connect your arguments to your evidence. Number your attachments and refer to them by number in the body of your letter.

5. State the outcome you want

Be specific about what you are asking for. Whether it is payment of the full claim amount, a reassessment, or a revised cash settlement, say so clearly. Vague requests get vague responses.

6. Note the response timeframe

Close your letter by noting that under the General Insurance Code of Practice, you expect a written response within 30 calendar days. Add that if the dispute is not resolved to your satisfaction, you intend to escalate the matter to AFCA.

Getting the tone right

Your letter should be firm, professional, and factual. You are making a reasoned argument, not venting your frustration. The person reading your letter is more likely to take it seriously if it reads like a well-prepared submission rather than an angry email.

Avoid emotional language, personal attacks on staff members, threats of legal action (unless you genuinely intend to follow through), and sweeping statements like "this is unfair" without explaining why. Every claim you make should be backed by a PDS reference, a piece of evidence, or a legal provision.

Common mistakes to avoid

• Sending a general letter that says "I disagree with your decision" without explaining why. Your insurer will simply restate their original position.
• Failing to reference your PDS. The policy wording is the foundation of your dispute. If you do not engage with the specific clauses, your argument lacks weight.
• Not keeping copies of everything you send. Always retain a copy of your letter and every attachment, and send it by email or registered post so you have proof of delivery.
• Waiting too long. While there is no strict deadline for IDR complaints in most cases, delays can weaken your position and push you closer to AFCA's time limits.

What happens after you send it

Once your insurer receives your IDR letter, they must acknowledge it within one business day. They then have 30 calendar days to investigate and provide a final written response. If they need more time, they must write to you explaining why and provide an estimated timeframe.

If the insurer overturns their decision, that is the end of the matter. If they uphold their denial, their response must include information about your right to take the complaint to AFCA. You then have two years from the date of the IDR response to lodge an AFCA complaint.

When you need professional help

Writing an effective dispute letter takes time, a solid understanding of policy wording, and the ability to construct a persuasive argument grounded in evidence. Many people find this overwhelming, particularly when they are already dealing with the stress of property damage, a car accident, or another insured event.

The Fair Claims Co specialises in preparing dispute documents and AFCA submissions for everyday Australians. We review your policy, analyse the insurer's reasoning, and build a structured response that addresses every denial point with the right evidence and legal references. If your claim has been denied or underpaid and you are not sure where to start, we can help you put your best case forward.

Once you have sent your letter, read what happens after you send a dispute letter so you know what to expect from your insurer and what to do if they reject your dispute.