What Evidence Do You Need to Prove Damages? Practical Guide for Civil & Injury Claims

Courts don’t pay for pain-they pay for proof. If you can’t back up what you lost with solid evidence, you’ll get nowhere fast. This guide shows you the exact documents, experts, and simple steps that actually move the needle when you’re trying to prove damages. I’m writing from Sydney, so the examples and references lean on Australian practice (think Evidence Act 1995 (NSW), Civil Liability Act 2002 (NSW), and leading High Court cases), but the playbook works across most common-law courts.

TL;DR: The Evidence That Proves Damages

Short on time? Here’s the punchy version. Use this to stress-test your file before you talk to a lawyer or insurer.

• Medical and expert proof link the harm to the event: GP and hospital records, imaging, specialist reports, and an independent medico-legal opinion that nails causation and impairment. Without this, non-economic loss and future care usually crumble.
• Money trails prove economic loss: payslips, tax returns, BAS, bank statements, invoices, employment contracts, rosters, and accountant letters. For self-employed, detailed pre- and post-event financials are essential.
• Out-of-pocket spend needs receipts: invoices for treatment, medication, travel to appointments, equipment, home modifications, and repair/replacement for damaged property. No receipt? Use secondary proof-bank statements, photos, or supplier quotes.
• Care claims live or die on logs: daily care diaries (hours, tasks), carer statements, and expert functional assessments. See Griffiths v Kerkemeyer (1977) for gratuitous care principles commonly applied here.
• Future loss rests on credible assumptions: medical prognosis, return-to-work capacity, actuarial/forensic accounting calculations, and Malec v J C Hutton (1990) style probabilities for future scenarios.

prove damages is not about telling a sad story; it’s about stacking reliable, relevant, and admissible evidence that lines up with each head of loss. Evidence law basics matter: relevance (Evidence Act 1995 (NSW), s55), hearsay exceptions (business records, s69), and expert opinion (s79).

“Where any injury is to be compensated by damages, in settling the sum of money to be given … you should as nearly as possible get at that sum of money which will put the party who has been injured … in the same position as he would have been in if he had not sustained the wrong.” - Livingstone v Rawyards Coal Co (1880) 5 App Cas 25

Step-by-Step: Gather, Quantify, and Present Evidence That Sticks

You don’t need to be a lawyer to build a convincing file. Think like an auditor: every dollar claimed should be backed by a document, a credible witness, or an expert. Here’s a clean workflow.

1. Map your heads of damage first

   • Non-economic loss: pain, suffering, loss of enjoyment (subject to thresholds/caps under your state’s civil liability laws).
   • Past economic loss: wages, profits, lost shifts, missed contracts.
   • Future economic loss: reduced earning capacity, promotion delays, retraining.
   • Care and domestic help: paid and unpaid (family/friends) care, domestic assistance.
   • Medical and rehabilitation: GP, specialists, physio, psychologist, meds, equipment.
   • Property damage: repair or replacement value, loss of use.
   • Incidental losses: travel to treatment, parking, data/phone if relevant to the claim, interest.

2. Lock down causation with medical evidence

   • Collect GP notes, hospital discharge summaries, imaging reports, specialist letters. Make sure the file shows a clean timeline: incident → symptoms → diagnosis → treatment → residual issues.
   • Ask your doctor for a letter that deals with causation in clear terms (e.g., “on the balance of probabilities, the collision caused the rotator cuff tear”). Opinions should be reasoned, not bare conclusions (Evidence Act s79).
   • For mental harm: you usually need a recognised psychiatric diagnosis (e.g., PTSD), a clear link to the event, and a prognosis. Symptom notes alone rarely carry the day.

3. Prove past income loss with documents, not guesses

   • Employees: payslips (3-12 months pre-incident), group certificates/Income Statements, tax returns, bank deposits, roster changes, HR emails about missed shifts.
   • Self-employed: two years of tax returns and BAS, profit & loss, invoices, job pipeline records, and a brief accountant letter explaining the business model and seasonal swings.
   • Show specific lost opportunities: emails cancelling gigs, tenders withdrawn, client statements, contracts you couldn’t fulfil.

4. Quantify future loss using reasonable assumptions

   • Start with medical capacity: What can you lift, sit, stand, and do repetitively? Occupational therapy and vocational assessments help.
   • Use Malec v J C Hutton logic: where the future is uncertain, courts can apply probabilities (e.g., 70% chance you can return part-time in 12 months).
   • Get a forensic accountant to model income under different scenarios using your real earnings, not generic averages.

5. Back care claims with time-and-task evidence

   • Keep a daily care diary: who helped, what they did (e.g., showering, transfers, cleaning), and how long it took. Note any paid invoices.
   • Courts in Australia often apply Griffiths v Kerkemeyer: you can recover for reasonable and necessary care provided by family/friends even if unpaid, subject to statutory thresholds and caps in your state.

6. Document special damages (out-of-pocket)

   • Receipts for treatment, medication, braces/splints, therapy apps, equipment, and home mods. Where you’ve lost receipts, use bank statements, pharmacy printouts, or supplier confirmations.
   • Travel to treatment: keep a mileage log, parking receipts, public transport statements.

7. Prove property damage with valuation-style evidence

   • Repair quotes (minimum two is safe), high-res photos (date-stamped), pre-incident condition evidence (service records), and if written off, a market valuation from a recognized guide or valuer.
   • Loss of use: rental invoices for a replacement, or a reasonable daily rate if you can support it with market comps.

8. Show you mitigated your loss

   • Follow treatment plans. Document job-seeking or modified duties conversations. Keep receipts for aids that helped you get back to work sooner.
   • Courts reduce damages if you unreasonably refuse treatment or fail to look for alternative work.

9. Build an evidence bundle that’s admissible

   • Relevance (s55) and reliability first. Use business records (s69) to get around hearsay for routine invoices/medical records. Expert reports must state the facts and reasoning (s79, Makita v Sprowles principles).
   • Lay witnesses prove what they saw, heard, or did. Don’t let them stray into opinion unless it’s a permitted shorthand (e.g., “he looked pale and unsteady”).

10. Present with a simple narrative and a clean spreadsheet

    • Create a one-page chronology: date, event, the document that proves it.
    • Use a damages schedule with each head of loss, the evidence source, and the total. Make it easy for an insurer or judge to say “yes”.

Why this structure works: it answers the two questions every court asks: “Is it caused by the defendant?” and “Is the amount reasonably proven?” High Court signposts like Medlin v State Government Insurance Commission (1995) and Malec v J C Hutton (1990) help anchor causation and the future-loss probabilities.

Examples, Checklists, and FAQs

Here are grounded scenarios, quick checklists, and straight answers to the questions people ask right after “How do I prove damages?”

Example 1: Car crash, broken wrist, six weeks off work (NSW)

• Causation: ED record showing FOOSH injury (fall on outstretched hand) after collision; x-ray; ortho clinic notes; physio plan.
• Non-economic loss: pain diary with functional limits (typing, driving, lifting); GP notes support sleep disturbance and limitations.
• Past income loss: payslips (3 months pre-incident), employer letter confirming rostered shifts missed and rate; bank deposits corroborate.
• Medical costs: receipts for cast, imaging gap, physio blocks, pain meds; parking receipts.
• Care: partner’s care diary for showering/meal prep 45-60 minutes daily for 4 weeks; OT notes confirm need.
• Mitigation: return-to-work plan with modified duties at week 5; physio discharge summary.

Example 2: Contract breach-supplier delay kills a retail launch

• Causation: signed supply agreement; email chain showing confirmed delivery date; notice of delay; contemporaneous notes of missed marketing window.
• Loss: sales pipeline analysis comparing last year’s launch week vs current; Shopify/PoS reports; ad spend wasted; discounting to clear stale inventory.
• Quantification: accountant report modelling expected vs actual revenue; proof of fixed costs; evidence you tried to source an alternative (mitigation).
• Property-like loss: storage and rework invoices; customer refunds logs.

Example 3: Defamation-lost speaking gigs

• Causation: publication screenshots, metadata, traffic metrics; client emails cancelling with direct reference to the publication.
• Loss: prior fee history, signed engagement offers withdrawn, accountant letter; diary of enquiries that evaporated post-publication.
• Non-economic harm: treating psychologist diagnosis if claimed; testimony from colleagues about reputational harm (careful with hearsay).

Quick checklists

• Medical proof pack: referral letters, imaging reports, treatment summary, prognosis, medication list, capacity certificate, pain diary (weekly entries).
• Income loss pack: payslips, tax returns (2 years), bank statements, employment contract, roster screenshots, HR/manager emails, gig confirmations, invoices.
• Care pack: daily log (task + minutes), carer statement, OT report, any paid invoices.
• Property pack: photos (pre/post), two repair quotes, valuation report (if write-off), service history, hire invoices.
• Mitigation pack: job applications, retraining receipts, treatment adherence, return-to-work plan.

Heuristics and rules of thumb

• Document within 48 hours of the event. Contemporaneous notes carry weight.
• One claim, one folder. Sub-folders by head of damage. Use filenames like “2025-03-12_physio_receipt_$85.pdf”.
• No receipt? Pair a bank statement with a supplier confirmation or reissued invoice.
• Self-employed? Your accountant is your best witness. Get them in early.
• Photos win arguments. Shoot wide, then close-up, with something that shows scale and date.

Pitfalls to avoid

• Assuming a doctor’s brief sick note proves long-term incapacity. It doesn’t. You need a detailed capacity opinion and prognosis.
• Ignoring mitigation. If you refuse reasonable treatment or light duties, expect a haircut on damages.
• Letting lay witnesses stray into expert territory. Keep them to facts and lived experience.
• Cherry-picking documents. Disclose the lot. Incomplete records look worse than bad records.

Mini‑FAQ

• What if I’ve lost key receipts?

  Ask providers for reprints or itemised statements. Use bank statements and supplier quotes as secondary proof. Add a short affidavit explaining the gap.

• Do I need an expert for every claim?

  No. But for medical causation, complex future loss, or specialised valuations, an expert is often decisive. Courts rely on reasoned opinions tied to facts on the record.

• How do courts treat future uncertainties?

  They estimate using probabilities (Malec). Your job is to supply the inputs: medical prognosis, capacity evidence, and earnings history so a fair probability can be applied.

• Can I claim for family care?

  Often yes, subject to statutory thresholds and reasonableness. Keep a care diary and get an OT assessment. Griffiths v Kerkemeyer lays the foundation used widely here.

• Will thresholds/caps block my non‑economic loss claim?

  Possibly, depending on your state and the scheme (motor accident, public liability, workers’ comp). A medico‑legal impairment assessment usually decides this.

• Can social media help or hurt?

  Both. Photos and posts can corroborate activity limits-or undermine your case. Assume insurers will check.

Next steps / Troubleshooting

1. List every head of damage you think applies. If in doubt, include it in a “watch” column.
2. Request your complete medical file and imaging on USB. Ask your GP for a causation/prognosis letter in plain English.
3. Export income data: payslips, tax returns, BAS, bank CSVs. Draft a simple pre‑/post‑incident earnings chart.
4. Start or tidy your care diary. Get an OT or physio functional capacity assessment if you’re claiming care or work limits.
5. Get two repair quotes or a valuation for property damage. Take better photos than you think you need.
6. Draft a damages schedule: each head, each document, each dollar. Highlight any gaps and plan how to plug them.
7. If your claim is sizable or complex, brief a lawyer early. Ask them to sanity‑check causation, thresholds, and expert needs. Mention Evidence Act admissibility and the Makita principles so the report is court‑ready.

Legal compass, not legal advice: The core idea doesn’t change in 2025-damages follow proof. Line up causation, quantify with documents, and show you did your best to limit the harm. Do that well, and you give any judge or insurer the easiest possible path to saying “yes”.