Five marketplace seller routes compared on one England job without changing the question

A useful marketplace seller software supplier comparison puts every route through the same job and evidence test. This one concerns a fictional England merchant moving one approved product record, stock position and later order states between its source system and one authorised marketplace account.

No supplier is named and no winner is declared. Research closed on 6 September 2026. Commercial amounts, weights, thresholds and service levels remain blank because no exact offer or controlled result was supplied.

Use one comparison unit

The unit is one complete execution of the predeclared fictional fixture, followed by export and isolated restore. The product population, identifiers, state vocabulary, evidence date and test environment must be identical for every route.

The fixture includes approved and rejected product changes, conflicting stock, corrected total price, an unselected optional extra, duplicate, late and rejected events, cancellation, partial refund, dispute, suppression, refused tracking, revoked privileged access, accessible staff and customer tasks, rollback, export and restore. No public listing, real order, payment or customer message is permitted.

Compare five routes without changing the question

Route	Evidence the buyer must obtain	Main exposure to investigate	Exit proof
Current manual process	Current steps, owners, source records and error history	Human hand-offs, account permissions and reconciliation	Demonstrate that the documented process can resume
Existing account configuration	Exact account feature, permission, schema, limits and change record	Marketplace dependency and constrained configuration	Export available records and restore the prior setting
Buyer-built integration	Code owner, interface contract, tests, deployment and maintenance evidence	Buyer capacity, interface change and privileged access	Rebuild from controlled source and retained code
Hosted tool	Exact supplier, service, edition, contract, subprocessors and support	Supplier change, data handling, access and portability	Export, revoke, delete and restore independently
Managed service	Supplier plus named operating role, authority, process and access records	Human intervention, subcontracting, accountability and continuity	Remove access and return the task with complete evidence

This is a route comparison, not a claim that every marketplace offers the relevant interface. Permission must be proved for the named account from its current first-party terms and configuration.

Keep consumer and safety gates outside the score

Each route must preserve product facts, traceability, price, optional choice and later correction. GOV.UK's online-selling guidance identifies description, price, delivery, ordering and confirmation fields. Mandatory fees, taxes and charges are among the subjects of the CMA's price-transparency guidance. Those records define questions for consumer counsel; they do not approve a route.

For goods, OPSS product-safety advice requires attention to actual supply-chain roles, territory and product-specific rules. A route stops if it drops a required identifier, warning, traceability field or withdrawal instruction.

Compare data and security evidence consistently

Use the same fields for purposes, controller and processor facts, subprocessors, transfers, retention, rights help, deletion and device storage or access. The ICO's controller-processor contract page remains under DUAA review, so its status and publication-day check belong in every dossier.

Security evidence covers authentication, minimum privilege, logs, support access, incidents, protected copies and recovery. NCSC's SaaS security guidance is useful for the hosted route but is not certification. Apply equivalent buyer questions to the other routes.

Record money and decision status

For each candidate, enter currency, VAT basis, charging unit, period, term, limits, internal labour, pass-through costs, correction, migration and exit. Do not compare a licence price with a managed-service total. HMRC's VAT records page supports the evidence categories, while an accountant decides the actual treatment.

The final record shows observed fixture outputs, missing evidence and separate gate outcomes. A buyer may choose only among routes that pass every required gate. If none does, retain the current process or stop the project rather than manufacture a winner.