If you're disputing an online purchase or service, start by downloading the records that answer four questions:

1. What did the seller promise?
2. What did you order, and what did you pay?
3. What happened after payment?
4. How did you ask the seller to fix the problem?

Save those records before a listing changes, a chat expires, or an account is closed. A screenshot can help, but it rarely proves the entire claim. The merchant, marketplace, card issuer, and a court may also use different procedures, so one set of evidence may not work equally well in every forum.

This is general information for U.S. consumers, not legal advice. Deadlines and remedies can depend on the state, contract, forum, and payment method.

Choose the route that fits the dispute

The route you use affects both the evidence you need and the deadline you must meet.

The FTC's online shopping guidance says a seller must ship an order as promised. If the seller did not promise a shipping time, the FTC says the seller generally must ship within 30 days after receiving the buyer's name, address, and payment, or permission to charge the account. That rule does not replace the seller's contract terms or a marketplace's dispute procedure.

For a qualifying credit-card billing error, the FTC's billing guidance says to dispute the error in writing within 60 days after the first statement containing the error was sent. The issuer generally must acknowledge the dispute in writing within 30 days, unless it has already resolved the problem, and resolve it within two billing cycles and no more than 90 days. Keep proof that the issuer received your notice.

Those credit-card rules don't automatically apply to a debit card, prepaid card, ACH transfer, wire, or payment app. Check the procedure for the payment method you actually used.

Build the record around four questions

1. What was promised?

Preserve the offer as you saw it, including the parts that may seem routine:

• Product or service page
• Price, shipping charge, taxes, and delivery promise
• Description, specifications, warranty, or service scope
• Return, cancellation, renewal, and refund terms
• Subscription trial and recurring-price disclosures
• Marketplace listing and seller identity
• Terms of service in effect when you placed the order

Record the page URL and the date, time, and time zone. Save a PDF or full-page screenshot, not just a crop of the price or advertising claim. Keep enough surrounding content to show the relevant conditions.

For a subscription, include the signup page, trial end date, renewal price, cancellation instructions, and cancellation confirmation. For an online service or freelance project, preserve the agreed scope, milestones, deadlines, revision terms, and acceptance criteria.

2. Did you order and pay?

Keep the complete order confirmation, invoice, receipt, and payment record. Helpful details include:

• Order or transaction number
• Merchant name and contact information
• Amount and currency
• Date and time
• Payment method
• Items or services purchased
• Shipping address, where relevant
• Merchant descriptor shown on the statement

A card statement can show that a charge occurred. By itself, it usually doesn't show that the seller delivered the item, performed the service, or supplied what was advertised.

Before sending records to a seller, marketplace, issuer, or court, remove full card numbers, security codes, passwords, account-recovery information, and unrelated transactions. Keep an unredacted original in a secure location in case you need to verify the copy later.

3. What happened after payment?

Compare the promised performance with what actually happened.

For a physical order, keep:

• Carrier tracking and delivery scans
• Delivery date and location
• Photos of the package, label, and contents
• Photos showing damage or a material mismatch
• Return authorization and return tracking
• Replacement or repair estimates

For a digital product or subscription, preserve access errors, download records, account notices, billing history, and cancellation screens. For an online service or freelance project, keep delivered files, version history, milestone submissions, approval messages, and records of missing work.

Keep the original photo and video files when possible. Make edits or annotations on copies so the originals remain unchanged.

4. Did you give the seller a chance to fix it?

Save every refund request, cancellation request, support ticket, and reply. After a phone call, make a dated note of the number used, the representative's name if provided, the main statements, and any case number. Follow up by email so the requested remedy and the response are recorded in writing.

A useful file shows the sequence: your complaint, the solution you requested, the seller's response, and any continuing charge or loss. If you're claiming a financial loss, keep receipts for return shipping, replacement purchases, repair costs, or other directly related expenses. Whether a particular loss can be recovered depends on the contract and applicable law.

Preserve emails, chats, and screenshots

Email and messaging records can be useful evidence, including WhatsApp messages, texts, and marketplace chats. They aren't automatically binding, and they aren't automatically excluded. Their value depends on what they show, whether they can be authenticated, and whether the surrounding records support your account.

Use this approach:

1. Save the native record first. Download emails in their original format when available, including attachments. Use an official chat export if the app provides one. Keep the original thread instead of copying selected lines into a new document.
2. Keep the context. Preserve account names, email addresses, phone numbers, order numbers, dates, time zones, attachments, and the messages immediately before and after an important statement.
3. Use screenshots as support. A screenshot can show how a page or account appeared at a particular time, but it should supplement the underlying export or account record. Include the URL and device date and time when relevant.
4. Write down how you collected the files. Note who collected each file, when it was collected, where it came from, and whether it was downloaded, exported, or photographed.
5. Work from copies. Keep untouched originals. Use copies for highlighting, redaction, and annotations, and don't overwrite the originals.
6. Back up the set. Store copies in two secure locations. Open the files to confirm they work, and make sure the backup doesn't depend on continued access to the disputed account.
7. Act promptly. Sellers and platforms may have different retention periods. Download relevant records and request important account records as soon as a dispute starts to develop.

A hash, such as a SHA-256 value, can help show that a file hasn't changed since it was hashed. It doesn't prove that the source was truthful or that the file was collected correctly. Most small consumer claims don't require forensic software, but a documented collection process is more useful when the amount or technical complexity of the dispute increases.

How authentication works in a U.S. court

In federal court, Federal Rule of Evidence 901 requires evidence sufficient to support a finding that an item is what the person offering it says it is. The rule gives examples rather than one mandatory method, including testimony from a person with knowledge and evidence that a process or system produces accurate results.

For an online record, a foundation might include:

• Your testimony that you used the account and sent or received the message
• The sender address, account name, phone number, or other identifying information
• A complete conversation thread that matches known facts and related records
• Platform records or testimony from a records custodian
• Metadata, system logs, transaction identifiers, or other corroboration
• A reliable process used to collect and preserve the file

Authentication addresses whether a record is what you claim it is. It doesn't by itself prove that a contract existed, that the seller breached it, or that every statement in a message is admissible. Relevance, hearsay, privilege, contract formation, and damages are separate questions. State courts may apply different evidence rules.

For example, a genuine message saying "your refund is approved" may help show that someone made that statement. It doesn't necessarily prove that the sender had authority, that the refund was processed, or that the approval wasn't later withdrawn.

What common records can and can't prove

Blockchain and NFT transactions

A blockchain transaction can help when the dispute involves a digital asset, token, or smart-contract transfer. Preserve the transaction identifier, wallet addresses, token number, listing page, sale terms, payment record, and related messages.

On-chain data may show that a transfer occurred. It generally doesn't establish what the seller promised off-chain, who controlled a wallet, whether an image was original, or whether the buyer received promised intellectual-property rights. Never provide a wallet seed phrase or private key as evidence.

AI-generated material

An AI tool can help search, organize, or transcribe records, but keep the underlying messages, files, and account exports. Check every generated summary against its source. Don't submit an AI-rewritten message as though it were the original.

If a dispute depends on an automated system's output, the other side may ask how the system worked, what data it used, and whether the result can be reproduced. Treat AI output as a review aid unless the relevant forum accepts it for a specific purpose and you can explain how it was produced.

Assemble a readable evidence packet

A short, organized packet is easier for a seller, card issuer, mediator, or judge to review than a folder of unrelated screenshots. The goal isn't to include every screen you can find; it's to make the disputed sequence easy to verify.

Use this order:

1. Timeline: List the order date, promised date, payment, delivery or performance event, complaint, response, and continuing charges.
2. Offer or contract: Include the product page, service scope, subscription terms, and refund or cancellation policy.
3. Payment proof: Include the receipt, invoice, and relevant statement entry.
4. Performance proof: Add tracking, photos, access records, delivered files, or defect documentation.
5. Communications: Include the complete relevant email or chat thread, not only the line most favorable to you.
6. Resolution attempts: Add support tickets, refund requests, return records, and the seller's replies.
7. Requested remedy: State the action or amount you want and show how you calculated it.

Use descriptive names such as 01-order-confirmation.pdf and 04-tracking-record.pdf. Keep a private folder with the originals and a separate copy with unnecessary personal information removed.

Take the next step before a deadline passes

Write to the seller

State the order number, what was promised, what happened, and the specific remedy you want. Attach only the records needed to support those points. Ask for a written response, then keep the sent message and delivery confirmation.

Use the marketplace procedure

If you bought through a marketplace, open the case before the platform's stated deadline. Follow its upload requirements. Save the case number, submitted documents, and final decision.

A platform decision is a company determination. It isn't necessarily a court ruling about the contract, and it may not prevent you from considering another available route.

Dispute a qualifying credit-card billing error

Send written notice to the address identified for billing disputes, rather than relying only on the address for general customer service. Include the charge, amount, date, reason for the dispute, and copies of supporting records. Keep proof of delivery.

The FTC's 60-day period is tied to the first statement containing the error, not necessarily the purchase date. Don't assume that period applies to a debit card, bank transfer, payment app, or another payment method.

Check the contract before starting a formal claim

Look for a governing-law clause, forum-selection clause, arbitration requirement, notice procedure, and limitation period. If arbitration is required, the contract may specify how and where to start it. Small-claims procedures and monetary limits vary by state and court.

If the seller is outside the United States, the governing law, forum, service requirements, and enforcement options may be different. A U.S. evidence rule or consumer deadline may not control the entire dispute.

Get help when the stakes justify it

Consider a licensed attorney or local legal-aid service if the amount is substantial, the dispute involves fraud or identity issues, the contract requires arbitration, or you've received a lawsuit or formal preservation request. Continue preserving records while you decide what to do.

Mistakes that weaken digital proof

• Keeping only a cropped screenshot instead of the original page or message
• Editing dates, images, chat text, or file metadata
• Forwarding an email without retaining the original message and attachments
• Relying on one isolated message while leaving out the surrounding conversation
• Failing to save the terms in effect when you placed the order
• Confusing proof of payment with proof of delivery or performance
• Missing a marketplace or credit-card deadline
• Sending a full card number, password, private key, or unrelated personal data
• Treating a blockchain confirmation or AI summary as proof of every disputed fact
• Assuming that a merchant's silence, a chargeback result, or a platform decision automatically resolves the underlying legal claim

Download the order terms and first payment record now. Then preserve the original communications, build the timeline, and use the dispute procedure that matches how you paid.

Frequently asked questions

Can email and WhatsApp messages be used as evidence?

They can be. Preserve the complete conversation, account identifiers, timestamps, attachments, and related transaction records. Whether the messages authenticate the sender or establish a binding agreement depends on the facts and the rules of the forum.

Is a screenshot enough to prove an online purchase dispute?

A screenshot may support your account, but it's stronger when paired with the URL, capture date, native page or message export, order record, and a witness who can explain how it was obtained. A screenshot alone may not show the full terms or prove that the page wasn't altered.

What if the seller never gave a shipping date?

The FTC says an online seller generally must ship within 30 days if no shipping time was promised. Keep the product page, order confirmation, payment record, and delivery communications so you can show which promise and timing applied.

Does a blockchain record prove that an NFT seller broke the contract?

It can help prove an on-chain transfer or payment. It usually can't prove the seller's identity, off-chain representations, ownership of underlying intellectual property, or the value and utility promised in a listing. Preserve those off-chain records as well.

Do credit-card dispute deadlines apply to debit cards or payment apps?

Not automatically. Credit-card billing rules, debit-card procedures, bank-transfer rules, and payment-app policies differ. Identify the payment rail first, then check the provider's dispute instructions and deadline.