Evidence Needed to Prove Unpaid Invoices in Tribunal

You did the work. You sent the invoice. The client has not paid. Now you are taking them to tribunal — and the tribunal will not take your word for it. You need evidence.

Australian tribunals operate on documentary proof. If you cannot prove the debt exists, prove you delivered what you invoiced for, and prove the other party has not paid, you will lose. This guide sets out exactly what evidence tribunals expect when you file a claim for unpaid invoices.

The core documents every tribunal claim needs

Without these, your claim will typically fail or be struck out at the first directions hearing.

The invoice itself

Your invoice must be clear, dated, and addressed to the correct legal entity. It must specify:

• Invoice number and date of issue
• Your business name and ABN
• The debtor’s name and address (matching the party you are suing)
• Itemised description of goods or services supplied
• The amount due (including GST if applicable)
• Payment terms (e.g., “Payment due within 14 days”)
• Your bank account or payment details

If you issued multiple invoices, include all of them. If you issued a tax invoice under GST law, make sure it complies with Australian Taxation Office requirements.

The contract or agreement

If you had a written contract, service agreement, or purchase order, include it. This proves the parties agreed to the transaction, the scope of work, the price, and the payment terms.

If there was no written contract, you can still succeed — but you will need to prove the agreement through emails, quotes, or conduct. Tribunals accept oral contracts, but you must prove the terms.

Proof of delivery or completion

You must prove you actually did the work or delivered the goods. Acceptable evidence includes:

• Signed delivery dockets or receipts
• Completed job sheets or timesheets
• Photographs of completed work (timestamped if possible)
• Email confirmation from the client acknowledging receipt or completion
• Tracking details from courier or freight companies
• Sign-off documents or approval emails

If the client disputes the quality or scope of your work, this evidence becomes critical.

Payment records

Show the tribunal what has been paid (if anything) and what remains outstanding. Include:

• Bank statements showing partial payments received
• Payment receipts or remittance advices
• A clear statement of account showing invoice date, amount, payments received, and balance owing

If the client made partial payments and then stopped, this strengthens your case — it proves they acknowledged the debt.

Supporting correspondence

Tribunals want to see that you tried to resolve the dispute before filing.

Demand letters or payment reminders

If you sent a letter of demand, statement of account, or payment reminder, include it. This proves you notified the debtor, gave them a reasonable opportunity to pay, and attempted to resolve the matter without legal action.

Emails and text messages

Include any emails or SMS exchanges where:

• The client acknowledged the debt
• The client requested more time to pay
• The client disputed the invoice (and your response)
• You clarified the scope of work or payment terms

Print these out or save them as PDFs. Highlight the relevant sections. Do not submit 200 pages of irrelevant chat.

Phone call notes

If you had phone conversations about the debt, prepare a brief written summary noting the date, time, who you spoke to, and what was said (especially any admissions or promises to pay). This is not as strong as written evidence, but it helps establish the timeline.

Evidence of attempts to recover the debt

Tribunals favour parties who tried to resolve the matter before filing.

Formal demand letters

A properly drafted letter of demand citing the debt, the legal basis, and a deadline for payment strengthens your case. It proves you gave the debtor a final opportunity to pay.

Payment plan offers

If you offered a payment plan and the debtor agreed but then defaulted, include the payment plan proposal, any signed agreement, and evidence of missed payments.

Mediation or negotiation attempts

If you attended mediation or attempted to negotiate, include mediation certificates, correspondence proposing settlement, or any without prejudice offers (check with the tribunal whether these are admissible).

Additional evidence for specific situations

For construction or trade work

• Building permits or approvals
• Scope of works or specifications
• Before and after photos
• Supplier invoices for materials used
• Subcontractor invoices (if you engaged others)
• Certificates of compliance or inspection reports

For professional services

• Engagement letter or retainer agreement
• Timesheets or activity logs
• File notes or progress reports
• Correspondence showing work performed
• Expert reports or deliverables provided to the client

For goods sold

• Purchase orders or sales confirmations
• Delivery notes or packing slips
• Proof of title transfer (e.g., vehicle registration, ownership documents)
• Warranty or guarantee documents
• Product specifications or catalogues

For ongoing supply arrangements

• Credit application or account opening documents
• Terms and conditions of trade
• Previous invoices that were paid (proving the relationship)
• Account statements showing payment history

What tribunals will not accept

Hearsay without supporting documents

“My mate told me the client said they would pay” is inadmissible. Tribunals need direct evidence.

Unsigned or undated documents

If your invoice has no date, or your contract is unsigned, the tribunal may question its validity.

Incomplete or vague invoices

An invoice that says “Services rendered — $5,000” with no breakdown will be challenged. Tribunals expect itemised invoices.

Evidence obtained improperly

Do not submit recordings of phone calls unless you told the other party they were being recorded. Do not submit documents you obtained unlawfully.

Irrelevant character attacks

The tribunal does not care that the debtor is a “difficult person” or has a bad reputation. Stick to the facts of the debt.

How to organise your evidence bundle

Tribunals appreciate well-organised evidence. Follow this structure:

1. Cover sheet — list of all documents included, numbered sequentially
2. Statement of claim or application — the tribunal form you filed
3. Your witness statement — a chronological summary of events in your own words, referring to the documents by number
4. Core documents — invoice, contract, delivery proof, payment records
5. Correspondence — emails, letters, demand letters, in date order
6. Supporting documents — anything else relevant, clearly labelled

Number every page. Use tabs or dividers if submitting a physical bundle. If filing electronically, use clear file names (e.g., “Invoice-12345-dated-2024-03-15.pdf”).

What to do if you are missing key evidence

If you do not have a signed contract, or you cannot find the delivery docket, you can still succeed — but you need to fill the gaps.

No written contract?

Prove the agreement through email exchanges discussing the work and price, quotes or proposals you sent that were accepted, evidence of part performance (you did the work, they accepted it), or previous invoices that were paid under the same arrangement.

No delivery proof?

Use photos of the completed work or delivered goods, email from the client acknowledging receipt, evidence the client used or benefited from what you supplied, or witness statements from others who saw the delivery or completion.

No payment records?

Prepare a simple statement of account yourself, showing invoice date and number, amount due, payments received (if any), and balance outstanding. If you have bank statements showing payments, attach them. If not, your sworn statement is still evidence.

Final checklist before filing

Before you submit your tribunal application, confirm you have:

• [ ] All invoices, clearly itemised and dated
• [ ] The contract or evidence of the agreement
• [ ] Proof you delivered the goods or completed the work
• [ ] Payment records or statement of account
• [ ] Demand letter or payment reminders
• [ ] All relevant emails and correspondence
• [ ] Your witness statement explaining the chronology
• [ ] Documents organised and numbered sequentially

If you are missing any of these, gather them now. Tribunals typically will not adjourn to give you time to find documents you should have brought in the first place.

How Claim Done prepares your tribunal evidence

Claim Done’s tribunal application service drafts your application and a witness statement from your evidence. You tell us about your invoices, contracts, emails, and proof of delivery. Our Programmatic Algorithms work from your answers, identify gaps, and draft:

• Your application for your state’s tribunal or court
• Witness statement linking your evidence to the legal elements of the claim

The service is a flat fee. No subscription. Prepared in about 5 minutes. Available for all Australian states and territories. Start your tribunal application now.

Frequently Asked Questions

Can I win a tribunal case without a written contract?

Yes. Australian tribunals accept oral contracts. You need to prove the agreement through emails, quotes, conduct, or part performance. If the client accepted your work or paid previous invoices under the same arrangement, that proves the contract existed.

What if the client claims the work was defective?

You need evidence the work met the agreed standard. Include photos of completed work, sign-off emails, compliance certificates, or expert reports. If the client used or accepted the work without complaint for weeks or months, that weakens their defective work defence significantly.

Do I need a letter of demand before filing at tribunal?

Not legally required in most states, but tribunals strongly favour parties who tried to resolve the dispute first. A letter of demand proves you gave the debtor a final opportunity to pay and shows you acted reasonably. It also increases the chance they will pay before the hearing.

How far back can I claim unpaid invoices?

Limitation periods vary by state, but most tribunal claims for debt must be filed within six years of the invoice due date. If the debtor acknowledged the debt in writing or made a partial payment, the limitation period may reset from that date.

What happens if I do not have proof of delivery?

You can still succeed with alternative evidence: photos of completed work, emails from the client acknowledging receipt, evidence they used what you supplied, or witness statements. If the client does not dispute delivery in their defence, the tribunal may accept your sworn statement as sufficient proof.