Complaint evidence checklist and personal-data safety

Understand the problem before writing

Good evidence makes a complaint easier to assess, but more attachments do not always produce a stronger case. Select documents that connect directly to the issue, identify what each record proves and remove information that the recipient does not need. A clear timeline supported by three relevant documents can be more useful than dozens of unrelated screenshots.

Common evidence includes application acknowledgements, transaction receipts, account statements, support tickets, official correspondence, contracts, photographs and written decisions. Distinguish an original document from a summary or inference and preserve the date on which it was created or received.

Financial and identity information should be shared carefully. Never include passwords, payment PINs, one-time codes, security answers or complete card details in a petition. Mask account or identity numbers where the full value is not necessary, and use a trusted verified channel if a responsible institution legitimately requests additional information.

Complaints involving medical treatment, children, employment records, detention or vulnerable witnesses require additional care. Explain the relevant facts without publishing an unrelated diagnosis, another person's private correspondence or confidential evidence that you are not authorised to disclose.

Build an evidence checklist

Use records that relate directly to your complaint. Put events in date order, identify the organisation involved, and keep copies of every message or acknowledgement. Describe what your documents actually show; do not present an allegation as a proven finding.

• A dated summary of the relevant events
• The original decision, transaction or application reference
• Records identifying the responsible institution
• Proof of prior contact and any complaint reference
• Only the documents needed to support the requested remedy
• Redaction of passwords, PINs, full identity numbers and unrelated data

Choose the institution that can respond

Send evidence only through an official verified email address, secure complaint portal, recognised physical registry or another legitimate channel. Check that the recipient is authorised to handle the issue and keep a record of what was submitted.

A company mentioned in a statement, address, receipt or background document is not automatically the institution responsible for the complaint. Identify who provided the disputed service, who made the decision, and who can supply records or correct the problem.

Decide whether escalation is justified

When escalating, provide the earlier complaint, response, unresolved issue and the minimum additional evidence necessary for the oversight body to understand the case. Do not assume that a regulator or public agency should receive every private document collected during the original dispute.

Before escalating, keep the original complaint reference, the institution's written answer where available, and a concise explanation of what remains unresolved. Check the current instructions published by the relevant authority instead of assuming that one deadline applies to every type of complaint.

Worked example: applying the route in practice

For a disputed loan deduction, provide a redacted account statement, repayment schedule, mandate reference and the lender's correspondence. The statement proves the transaction history; it does not make the account-holding bank the responsible lender.

Avoid common mistakes and protect personal data

Do not alter screenshots, guess missing dates, share another person's confidential records or send identity documents to an unverified email address merely because it appears in a search result.

Remove passwords, one-time passcodes, card security codes and unrelated medical, financial or family information. Request a specific remedy supported by your evidence, such as an explanation, correction, investigation, refund or written decision.

Frequently asked questions

Official sources and contact starting points

These links point to the organisations' published websites or complaint resources. Check that the channel and procedure remain current before sharing your complaint or evidence.

• Nigeria Data Protection Commission
• National Human Rights Commission