Advertising checks for marketplace software offers, from substantiation to correction

Marketplace seller software advertising rules depend on the communication and actor, not on the tool that published it. This checklist was researched on 6 September 2026 for an England seller using one marketplace account. It gives non-compensating evidence gates, not a compliance verdict.

Classify the communication

• Name the legal seller, advertiser, publisher, marketplace and any commercial partner.
• Mark seller-supplied catalogue fact, editorial material, paid placement, affiliate content, sponsorship, review or endorsement separately.
• Record the audience, territory, channel, product population, publication date and expiry.

CAP Code recognition rules say non-broadcast marketing communications must be obviously identifiable. The Code is self-regulatory; legal duties and marketplace terms need separate review. A platform-provided label does not decide every context.

Substantiate the claim

• Copy the exact objective claim and overall impression into a claim register.
• Attach evidence for the named product, model, condition, population and period.
• Record the evidence owner, limitations, permitted channel and recheck trigger.
• Hold comparative, performance, safety or savings language that lacks matching support.

CAP's March 2026 misleading-advertising advice explains that overall impression, omissions and objective substantiation matter. It also states that the advice is not legal advice and does not bind the ASA or CAP panels. Product-safety counsel must review safety statements independently.

Inspect price and customer choice

• Check the invitation to purchase, total-price field and unavoidable charges at the point shown.
• Keep mandatory and optional amounts in separate evidence fields.
• Preserve the customer's positive choice for an optional extra.
• Reconcile the displayed offer with the order and correction record.

The CMA's price-transparency guidance, updated 7 January 2026, covers mandatory charges and pricing presentation. GOV.UK says optional extras require express consent. Consumer counsel must assess the actual facts and any exceptions.

Keep promotion settings visible

• Record whether a marketplace placement is organic, seller-paid, supplier-funded or controlled by another commercial party.
• Capture the exact placement label as presented, not only the back-office campaign setting.
• Check whether targeting or personalisation introduces a separate data purpose or device operation.
• Keep audience exclusions, product restrictions and channel expiry with the claim record.

Test the consumer-facing rendering with synthetic or specifically authorised content. A dashboard setting does not prove that a person saw a clear label beside the claim. Advertising approval cannot authorise tracking or establish that a restricted product may be promoted.

Review the whole offer after a change

A corrected headline can still leave an old image, comparison, delivery statement or review in another placement. Search by product identifier and claim ID across the listing, advert, affiliate material and saved campaign variants. Record what was checked, who checked it and when each channel acknowledged withdrawal.

Keep ordering disabled during synthetic checks. Cover a rejected optional choice, corrected product fact and expired endorsement without charging a customer or generating a public review.

Control reviews and endorsements

• Separate genuine customer evidence from seller or supplier statements.
• Record incentives, commercial interests, permission and the relevant experience.
• Do not convert a review about one product or period into a broader claim.
• Preserve screening, removal, correction and complaint evidence.

CAP's July 2026 testimonials and endorsements advice addresses genuineness, documentary evidence and commercial interests. The DMCC unfair-practice provisions also include specific review practices. Advertising and consumer-law reviewers must each sign their own gate.

Correct promptly without erasing history

• Pause the ad or listing when evidence expires, a price changes or a safety issue appears.
• Retain the old version, reason, authoriser and affected placements.
• Confirm correction or withdrawal in each channel and accessible format.
• Recheck any tracking or audience-list processing with the privacy adviser.

A disclosure cannot cure an unsupported claim, hidden charge or unsafe product. Publication remains on hold until named reviewers approve the exact communication and evidence version.