Marketplace software service standards chosen around customer harm

Marketplace seller software service standards are useful only when they define an event, eligible population, unit, clock, evidence and response to failure. This guide sets no availability, accuracy or response target. The fictional England seller must fill thresholds from its risk, capacity and reviewed contracts.

Research closed on 6 September 2026. No supplier service, marketplace connection or live order was measured.

Label the kind of standard

A buyer standard states what the merchant requires. A contractual commitment is wording accepted by identified parties for an exact service and term. A supplier claim is an attributed statement awaiting verification. An observation is a measured result for a named version and period. A regulatory requirement comes from the applicable authority and trigger. Do not present one class as another.

NCSC supplier-assurance questions prompt buyers to examine incident management, remote access, continuity, reporting and contract exit. They provide questions, not an SLA or certification.

Complete the definition card

For each proposed standard, record:

Field	Buyer entry
Event and state	[exact product, stock, order, payment or support event]
Eligible population	[included records and exclusions]
Measure	[count, proportion, elapsed time or other unit]
Clock	[start, stop, pause rule, timezone and late-data cut-off]
Evidence	[source, query, version, owner and retention]
Threshold	[blank until buyer-approved evidence exists]
Failure response	[contain, correct, escalate, roll back or stop]
Recheck	[contract, interface, volume or risk trigger]

An event described as "order complete" is too vague. Separate placement, acceptance, authorisation, capture, fulfilment, cancellation, return, refund, dispute and settlement. State whether duplicates, retries, staff tests and unresolved records enter the denominator.

Choose standards around customer harm

Product and price accuracy standards need the inspected version and evidence owner. GOV.UK online-selling guidance identifies description, price, ordering, correction and confirmation subjects. A failure response may withdraw an affected offer while open orders move to a customer-support queue.

For goods, product-safety gates cannot be averaged into catalogue quality. OPSS notification guidance addresses business reports about unsafe or non-compliant products. The specialist decides the actual response and authority; an operational target cannot postpone it.

Define evidence and recovery standards

Data standards specify permitted source, completeness rule, missingness, lateness, duplicate handling and correction history. Privacy permission is a separate gate. A faster event is not acceptable if a refused storage or access choice is ignored.

Security standards cover privileged access review, log availability, detection, containment and recovery evidence. NCSC secure online-service guidance distinguishes logging, security monitoring, transaction monitoring and incident management. Create separate measures rather than one security score.

Accessibility standards describe the user task, method, assistive setup where relevant, defect evidence, owner and retest. They must cover staff exception work and customer correction, refund and support journeys, not merely page rendering.

Make failure actionable

Every threshold needs an owner who can pause the affected state. The record must say what continues during containment, how customers and open orders are handled, what evidence permits restart and when rollback is required. Supplier escalation does not remove the seller's responsibility to preserve its records and routes.

Keep consumer, safety, tax, privacy and PECR, security, accessibility and exit as non-compensating gates. If the contract, system evidence and buyer definition use different clocks or populations, mark the standard UNRESOLVED. Do not manufacture a common percentage or choose the most favourable figure.