Quick answer
Collect evidence that links the legal parties to an agreed obligation, shows that your business performed, and explains the exact balance. The core proof usually includes registration details, the contract or accepted quotation, orders, delivery or completion records, invoices, credits, payment evidence and the full customer correspondence. Preserve negative evidence as carefully as supportive evidence because complaints, returns and scope changes determine the real dispute.
How to use this guide
Create an evidence map rather than a pile of documents. For each element—party, authority, agreement, performance, due date and amount—identify the best source record and any contradiction. That approach shows whether the business has a provable claim before money is spent on formal collection.
Prove the identity and authority of the parties
Keep company-registration material and onboarding records for both sides. Link trading names to registered entities and note any change in ownership or structure during the relationship. The person who sent an order should be connected to the customer through a title, prior course of dealing or another authority record.
If a director signed a suretyship, preserve the complete signed instrument and identity of the surety. Do not infer personal liability from an email signature or the fact that the director handled negotiations. For a ceded claim, the cession and collection authority belong in the proof map.
Demonstrate agreement on scope and price
Use signed contracts, accepted quotations, purchase orders, incorporated terms and messages recording amendments. If acceptance occurred electronically, retain the native email or message export with attachments and metadata. The Electronic Communications and Transactions Act supports the use of data messages, but authenticity, integrity and evidential weight still need to be shown. Record who exported each file, when it was collected, which system produced it and how the preserved copy was checked against the source. That chain helps another reviewer explain the record without relying on guesswork.
Oral agreements require careful corroboration. Record who participated, what was agreed and which later conduct confirms the terms. Do not ask a witness to sign a reconstructed contract; obtain a truthful statement or chronology that distinguishes memory from documentary proof.
Connect performance to each invoice line
For goods, match quantities and descriptions to dispatch records, courier tracking, signed delivery notes, collection logs and return documents. Photographs, serial numbers and stock records can resolve disputes about identity or condition. For services, use timesheets, milestone sign-offs, submitted work, meeting records, access logs and approvals.
Recurring or subscription billing needs proof of the renewal term, continued availability and the period charged. A general assertion that services were “always provided” is weaker than month-specific access or performance evidence. Keep records of remedial work and the customer's response.
Prove the net amount rather than the headline total
Build a ledger that allows another person to reproduce the balance. List every invoice, due date, payment, credit note, return, discount and allocation. Attach bank records or remittance advice for receipts, redacting unrelated information where lawful and appropriate.
For interest and costs, identify the clause or legislation relied on and show the calculation. The Prescribed Rate of Interest Act does not justify every percentage or collection fee, and different rules can apply to judgment or unliquidated debts. Keep principal and additions in separate columns.
Preserve dispute and acknowledgement evidence
Save the customer's entire explanation for non-payment and every response your business sent. An acknowledgement, part-payment or proposed plan may affect prescription, but its significance comes from the actual wording and context. Label without-prejudice communications accurately without assuming that a label makes every statement unusable for every purpose.
Build the prescription chronology using the due date, later conduct and served process. Many ordinary claims use a residual three-year period, yet the applicable period and commencement still require analysis. Courts do not raise prescription automatically for a party.
Evidence inventory
- Registered entity records, credit application and authorised contact details
- Contract, terms, quotations, orders and documented variations
- Delivery notes, tracking, completion certificates and acceptance records
- Native electronic messages with attachments and surrounding context
- Invoices, statements, credits, returns and an auditable ledger
- Bank receipts, remittance advices and payment allocations
- Complaints, remedial work, set-off assertions and proposed settlements
- Suretyship, security, cession, jurisdiction and dispute clauses
- Timeline of due dates, acknowledgements, demands and court process
Quality checks for the proof pack
- Can a third party trace each invoice line to the agreement and performance record?
- Are originals protected from annotations and later edits?
- Does the file contain the customer's strongest complaint, not only the creditor's version?
- Is every additional amount supported by a calculation and legal basis?
- Are the claimant and debtor legal identities consistent across documents?
- Can the source and collection date of electronic evidence be explained?
Important limitation
Evidence quality and admissibility are matter-specific. This checklist does not establish the debt, validate a suretyship or decide prescription. Preserve records lawfully, avoid unnecessary disclosure of personal information and obtain advice before relying on contested electronic or oral proof.
FAQs
What is the strongest proof besides the invoice?
The accepted contract or order and records connecting actual delivery or performance to the amount billed are central.
Should I keep customer complaints?
Yes. They are necessary to assess any defence, counterclaim, credit or remedial work.
Are WhatsApp messages usable as evidence?
They may be, but preserve the full export, participants, dates and context rather than relying on isolated screenshots.
How should I prove the balance?
Use an auditable ledger tied to invoices, payments, credits, returns and the basis for interest or costs.
Related Lexuno paths
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Source notes
- Prescription Act 68 of 1969
- Electronic Communications and Transactions Act 25 of 2002
- Prescribed Rate of Interest Act 55 of 1975
- Protection of Personal Information Act 4 of 2013
- KLD Residential CC v Empire Earth Investments 17 (Pty) Ltd [2017] ZASCA 98
- Companies Act 71 of 2008
- General Law Amendment Act 50 of 1956
Legal note
This article is general legal information for South African readers. It is not legal advice. Speak to a qualified legal professional about your specific facts before taking action.