A store conversion plan built on a defined journey and predeclared stop rules

Treat the plan as a sequence of release decisions, not a search for an assumed uplift. Follow the branches in order: define the customer transition, map its route, establish a reproducible baseline, test the proposed explanation, then clear protection and ownership gates. At any unresolved gate, hold, revise or retire rather than proceed.

If the customer transition is not yet named

If you cannot name the transition under review, do not select a fix. Identify the legal seller, product or service, population, channel, journey step, evidence period and safe route customers can use now. Check the relevant England rules before setting the decision boundary.

Map only states relevant to the business: browse, basket, checkout, payment authorisation, capture, order confirmation, fulfilment, cancellation, return, refund, dispute and support. Not every seller uses every state, so mark what applies instead of imposing a universal funnel. Record the evidence period and the safe route still available to customers.

For example, a filter seller might map its web store through browse, basket, checkout details, payment authorisation, order confirmation, dispatch, delivery, return and refund. The question could be the move from basket to checkout, with checkout errors in the event log serving as supporting evidence for review.

Name the transition that prompted concern and the evidence behind it. Failed authorisations and unclear delivery information point to different possible issues. A fall between basket and checkout could reflect stock, price, choice design, technical failure or incomplete measurement, so investigate before assigning a cause or choosing an intervention.

The government online selling guidance lists information sellers must give before an order and the required payment-button wording. Distance-selling guidance covers business identity, description, price, delivery, cancellation and contract information. These establish consumer boundaries, not conversion tactics.

Rule of thumb: Without a named transition, choose no fix.

If customers can use different sales routes

If a customer can complete the same task by website, app, marketplace or assisted service, map each route before selecting one. Seller identity, interface control, data access, payment role, fulfilment and support can differ. Do not combine unlike events or describe the routes as interchangeable.

For each path, record who makes the offer, accepts the order, handles payment, fulfils it, issues refunds and controls customer data. FCA payment-service-provider guidance describes differences in protections and gives a register-check boundary. FCA status is not endorsement, and a provider status does not settle the merchant consumer or tax responsibilities.

Use one money view across routes: gross order value, settled cash, refunds and disputes, variable costs, and net contribution are different measures. If records cannot be normalised, mark the field unknown and do not declare a winner. A merchant decision should use comparable states and measures, not a mismatched rate.

Rule of thumb: If route records cannot be made comparable, name no winner.

If the existing route cannot be measured again

If current performance cannot be described reliably, write down the existing route before altering it. Specify eligibility, start and completion events, numerator and denominator, measurement period and timezone, channel and seller, plus the definition version. Keep the record clear enough for another person to reproduce.

State how late events, duplicates, bots, staff activity and test orders are treated. Document rules for missing records and identity, as well as the date range, timezone and definition version. Leave unresolved fields visible; do not silently treat missing records as proof that customers were absent.

These figures describe one seller, not a market target or a promised result: numerator, completed checkouts, 1,180; denominator, eligible basket sessions, 4,720; period, 1 April to 30 June 2026; timezone, Europe/London; definition version, checkout-v3. Keep every field attached to the figure when reporting it.

Include post-order states, since an order being placed does not show that it was paid, fulfilled or retained. Report authorisation, capture, settlement, cancellation, return, refund and dispute separately. Define currency, VAT basis, period, refunds, chargebacks, variable costs and missing settlements; an accountant and tax adviser must review these definitions.

Use the simplest existing route as a baseline: the current page, telephone assistance or no change. Keep it available for diagnosis and recovery and, where the design permits, a credible counterfactual. A conversion rate alone proves neither causation nor customer benefit or orders retained after refunds.

Rule of thumb: Describe the existing route before changing it.

If the proposed change has no testable explanation

If a proposed change cannot explain how it might address the selected journey problem, record the current route and at least one alternative. Do not turn a suspected issue into a treatment until its proposed mechanism can be stated plainly and checked against the journey evidence.

Unclear delivery information might call for different wording or placement; a lost order state might need an operational remedy rather than more persuasive copy. Attach evidence and uncertainty to each option, separating customer observation, system event, supplier statement, legal requirement, editorial inference and unresolved question.

Record dependencies, affected populations, owners, costs, assurance work, reversibility and the condition that would disprove the suggested mechanism. Keep complaint, refund-state, accessibility-defect, security-incident and data-loss guardrails separate from the primary rate, so a gain in one measure cannot hide harm elsewhere.

Leave target values empty until the merchant approves them. A threshold depends on decision context, risk appetite and evidence; do not borrow one from another store, a supplier case study or a market average. State the proposed outcome and its uncertainty before setting an acceptance boundary.

Rule of thumb: Set no target before the merchant approves its evidence and risk context.

If a customer-protection check remains unresolved

If any required protection has not passed its acceptance check, do not optimise. Assess price information, optional charges, product claims, accessibility, tracking, payment integrity and cancellation routes separately. A higher observed completion rate cannot compensate for poorer customer choice or a transaction that is unsafe.

CMA price-transparency guidance addresses mandatory fees, taxes and charges, including drip and partitioned pricing. Its additional-charges guidance says online and app sellers need express agreement for optional extras, rather than relying on default opt-in. Check these requirements against the offer and the journey customers actually see.

Cancellation and refunds remain relevant after a purchase has been counted. The government returns guidance explains that online, mail and telephone orders can carry cancellation rights even where goods are not faulty, subject to exceptions. Obtain a qualified consumer review for the particular product and contract before clearing this route.

For goods, the product owner must maintain substantiation, supplier traceability and corrective-action routes. July 2026 OPSS product-safety guidance distinguishes Great Britain from Northern Ireland and says sellers must not sell products they know, or should know, are unsafe. Conversion work cannot override a withdrawal or warning, so keep this check independent of any rate target.

Before changing data collection, list every tag, cookie, script and pixel, including local-storage use and server-side matches. The ICO final April 2026 storage and access technology guidance explains current PECR and UK GDPR treatment, including exceptions and consent controls. Consider an exception only for its particular purpose, not for experimentation in general.

Do not make refusal harder, degrade a route when someone declines optional tracking, or count absent identifiers as absent customers. Keep consent status separate from measurement gaps. Before collection changes, the privacy owner should approve purpose, lawful basis, minimisation, retention, processors, access and deletion.

The CMA online choice architecture collection describes how website and app design can influence shopping decisions. It identifies potentially harmful practices, including pressure selling and hidden charges. Preserve an intelligible choice that customers can make freely, even where that choice reduces a narrow completion rate.

Rule of thumb: Do not optimise while any customer-protection check is unresolved.

If the journey may exclude disabled customers

If accessibility has not been assessed, include people using assistive technology, alternative input, magnification, captions or assisted service routes in the intended population and test design. Cover payment, confirmation, cancellation and support as well as the point where the journey starts.

Do not infer disability from a device or a person behaviour. Ask people what arrangements they use, then include those needs in the test instead of treating them as outside the population. The government Equality Act guide describes the Great Britain duty on service providers to anticipate barriers and consider reasonable adjustments.

Set release stops for keyboard traps, unusable error messages, lost focus, inaccessible authentication, missing alternatives or a support route that cannot complete the same task. A higher measured rate cannot justify excluding people whose journey was inaccessible or whose activity was absent from the denominator.

The accessibility specialist decides whether a defect blocks release. Apply that decision to the journey under assessment, including payment and post-order routes, rather than omitting an inaccessible step from the comparison. Accessibility evidence remains part of the release decision even when it does not change the primary rate.

Rule of thumb: Do not accept an inaccessible route as a valid comparison.

If the comparison cannot separate change from chance

If the comparison cannot support the claim being considered, predeclare the eligible population, allocation unit, exposure rule, intervention and comparison, primary outcome, exclusions, analysis period, missing-data treatment, uncertainty method, validity risks and stopping rule. Log stock, price, promotion, channel mix, outages and fulfilment changes that could affect interpretation.

One illustrative stop condition is to end exposure if a payment authorisation state is lost, an accessibility blocker is confirmed, or weekly completed checkouts remain below half the baseline count for two consecutive weeks. These are examples for one context, not universal thresholds for other stores.

HM Treasury May 2026 Magenta Book is government evaluation guidance, not a retail test manual. Its supplementary quality guidance for impact evaluation separates outcome monitoring, which shows whether an outcome changed, from causal attribution, which requires a suitable counterfactual and proportionate design.

Allocation does not remove ethical or operational risk. Do not expose anyone to misleading prices, unsafe products, broken payment handling, inaccessible controls or inferior cancellation rights. Use synthetic or specifically authorised cases for high-risk journey checks. Stop if a non-compensating gate fails, evidence integrity breaks or the approved exposure boundary is crossed.

Rule of thumb: Stop when the counterfactual or a non-compensating gate fails.

If nobody can pause and restore the change

If no one is authorised to stop exposure and recover the previous route, keep the change unreleased. Name the legal seller as owner of the customer promise and the product owner as controller of the change.

Analytics and experimentation owners maintain event and allocation evidence; payments, fulfilment and support owners check what happens after an order.

Consumer, accessibility, privacy and PECR, safety, security, finance and tax reviewers should each approve their specialist gate. NCSC secure online service guidance covers identity and access, logging, bots, supply chains and incident management. Translate these areas into named access owners, approved test data, monitored releases and a rollback that has been tested.

Keep the prior version, deployment evidence, data-definition version, approvals and restart authority with the change record. Before exposure starts, name who can pause it, withdraw a product, restore the old route, correct customer information and notify affected owners. A dashboard by itself does not establish that recovery can be carried out.

Rule of thumb: Keep the release on hold until named owners can stop and recover it.

If the evidence does not support release

If the record cannot support a safe decision, choose proceed, revise, hold or retire using the journey problem, baseline, comparison evidence, uncertainty, customer effects, post-order states, costs and every specialist gate. Before publication, named experimentation and statistical reviewers must check the design and the claims.

Named consumer, privacy and PECR, accessibility, product-safety, security, payments, accounting and tax specialists must review their own sections. This is general editorial information, not legal, financial or tax advice, an England benchmark or evidence that a store change will improve commercial outcomes.

Rule of thumb: Proceed only when evidence and every relevant specialist gate support release.