Marketplace seller software selection: five compliance gates

Selecting marketplace seller software should begin with the seller's job, not a feature list. Define the product records, stock movements and order changes the software would handle. Then set evidence gates a candidate must pass, so a strong score on one feature cannot hide an unresolved safety, security or data-exit question.

Each gate rests on a named UK source: the CMA's unfair commercial practices guidance and the Digital Markets, Competition and Consumers Act 2024, the General Product Safety Regulations 2005 and local Trading Standards, HMRC and the £90,000 VAT registration threshold, the NCSC Cloud Security Principles, and the UK GDPR duties the ICO enforces when processing ends.

Key takeaways for software selection

Start with a defined seller job, then assess consumer conduct, product safety, VAT records, cloud security and data exit. Give each gate its own evidence and decision. Compare candidates on the same tests, and keep unresolved questions separate from any overall feature score.

Define the seller job

Write down the products, identifiers, source records and marketplace account involved, such as an Amazon, eBay, Etsy or TikTok Shop seller account. Describe what should happen when product details change, stock conflicts or an order is cancelled. A clear specification gives the team a shared test, rather than relying on different assumptions about what a supplier's feature names mean.

Map the current process as well as the proposed one. Note the records entering and leaving each step, who can approve changes, and what the team would need to inspect after an error. The candidate's own functions set what can be tested: listing and feed management, multichannel stock synchronisation, order management and the VAT record reconciliation behind the third gate. Use the inventory software checks for UK marketplace sellers to frame stock questions, and a supplier guide to keep candidate tests focused on the same job.

Apply five evidence gates

Use the gates as pass, rework or stop decisions. Apply them to the seller's proposed workflow, rather than scoring features in isolation. Set the evidence needed for each gate before testing, and record any unresolved point rather than treating it as a pass.

The CMA unfair commercial practices guidance describes business conduct prohibited by the Digital Markets, Competition and Consumers Act 2024 as unfair business-to-consumer trading. Test whether the seller can review relevant offer information and choices before publication. Ask which listing fields the software exposes for that review, who can edit them and whether the change history is kept. Treat that review as a buyer control, not proof that the software itself establishes compliance.

Products must be safe in normal or reasonably foreseeable usage under the General Product Safety Regulations 2005. A business selling consumer products in the UK must not sell products it knows, or should have known, are unsafe. Products should only be sold if their compliance with product safety regulations has been demonstrated appropriately.

Include a safety escalation test. A seller made aware of safety risks or consumer incidents related to a product it sold has a legal duty to report them to the manufacturer, supplier or local Trading Standards service. Ask who receives the alert, which record is retained and how the seller confirms the report was made.

A business must register for VAT if its total taxable turnover for the last 12 months goes over £90,000. HMRC is the registration authority, and the application form is VAT1. Test whether the seller can obtain and reconcile records to assess turnover. Assign the tax decision to a responsible person, and use the VAT-registered seller checks to shape questions about those records.

The NCSC Cloud Security Principles apply to cloud platforms and Software-as-a-Service. Assess the cloud service and the company that runs it against each principle's goals. Consider what evidence gives enough confidence in the provider's statements. Record what the evidence establishes for the seller's intended use, rather than accepting an untested assurance.

At the controller's choice, a processor must delete or return personal data after processing services end. The processor must also delete existing copies unless domestic law requires storage. That duty comes from the UK GDPR, which the ICO enforces, so ask the supplier for the record it keeps of deletion or return. Define the expected return or deletion outcome before testing. Use the data protection checklist to organise questions about roles, retention and access.

Compare evidence, not promises

Separate supplier claims from contract terms, independent evidence and observations from the seller's tests. Use feature descriptions to identify what to test, rather than treating them as proof of fit. Record the evidence, reviewer and outcome for each gate, including anything the test did not establish.

Use the same test cases for each candidate. Include a corrected product record, a stock conflict, an order change and a safety escalation where relevant, and run each case through the candidate's own listing, stock and order screens rather than a demonstration script. Use the vendor due diligence questions to structure checks on the supplier and its answers. Limit each test result to the configuration and evidence actually reviewed.

Questions before the final decision

Keep a decision record with the job specification, current process, candidate evidence, unresolved questions, gate outcomes and the person authorised to decide. Use pass, rework, hold or stop as clear outcomes, and state what evidence would change a hold into a decision.

What must be checked before approval?

What happens when a gate is unresolved?

Do not move a candidate forward just because its overall score is high. Keep any unresolved gate visible, ask for the missing evidence, and repeat the relevant test after a change. Use the selection checklist to structure early rejection decisions, recording the reason and what would justify reconsidering the candidate.