Costs and pricing
How to record ecommerce conversion budget inputs
A framework for ecommerce conversion costs and pricing: record sourced budget inputs, map order states, and assign owners to six project stop rules.
What to take away
- Price one merchant decision across the whole order path, not just the payment button.
- A row without the fields needed for comparison remains unknown and stays out of the decision.
- A placed order is not cash receivedauthorisation, capture, refund and chargeback each carry separate rows.
- Agree six stop rules and name their owners before approving any spend.
- Keep the cash, accounting and economic views in separate columns.
Map the ecommerce conversion order path
Start at page view and finish at dispute. Each state costs money at a different moment. Only capture puts cash in the merchant account, and an authorisation is a promise rather than a receipt.
Order and payment states
- Page viewed
- Basket started
- Order placed
- Payment authorised
- Payment captured
- Order confirmed
- Fulfilled, retained, cancelled
- Returned, refunded, disputed
GOV.UK's guidance on online and distance selling sets out the information, total price and confirmation a shop must give before the contract forms. Returns and refunds continue after checkout, so support time belongs in the same budget. A budget that stops at the pay button leaves the post-order work unpriced.
Set an admission rule for every value
Give every monetary row the same fields before it can influence a decision:
- Legal supplier or internal cost owner.
- Exact service, edition or work package.
- Geography, evidence and access date.
- Currency, VAT basis, unit and quantity.
- Period, minimum term and limits.
- Captured page version and recheck date.
Admission rule for each value
- Legal supplier or internal cost owner
- Exact service or edition
- Geography, evidence and access date
- Currency, VAT basis, unit and quantity
- Period, minimum term and assumptions
- Captured version and recheck date
- Missing field -> unknown and hold
A row missing any field needed for comparison reads unknown, and the affected decision goes on hold.
VAT-registered shops need VAT-inclusive pricing and retained records, and HMRC's VAT records guidance lists what to keep. Registration is compulsory above £90,000 of rolling 12-month turnover, and the standard rate is 20%. Check the current figures, and let your accountant decide the actual treatment.
The store-change budget approach puts a source field on every row, making this admission rule easier to apply.
Example: a filled row and a rejected row
| Budget row | Status | Recorded fields | Decision |
|---|---|---|---|
| Accessibility audit | Ready | Accessibility lead, one site, 90-day quote validity, VAT exclusive, market range £3,000 to £15,000 from a named audit provider | Approve |
| Privacy consultancy | Blocked | Day rate blank, no source, no geography, no VAT basis | On hold |
The first row can be compared and signed off. The second cannot be used in any calculation, however plausible its number looks.
Compare fixed, retained, seat and outcome pricing
What is charged
- Fixed or project
- Agreed deliverables and acceptance
- Retained service
- Recurring period and service scope
- Seat or user
- Entitled identities
- Metered
- Sessions, events or visitors
- Outcome-linked
- A predeclared outcome
- Pass-through
- Third-party charges
What to record
- Fixed or project
- Scope, change control
- Retained service
- Notice period, included hours
- Seat or user
- Named users, minimum seats
- Metered
- Meter definition, duplicate rule
- Outcome-linked
- Baseline, attribution method
- Pass-through
- Evidence, mark-up rule
Affiliate commission in UK retail typically runs 5% to 15% of order value. These are contract mechanisms, not claims about how common each one is. Judge them on the same merchant case.
Agree six stop rules with named owners
Write these before the first invoice is approved:
- Spend above the approved ceiling or variancefinancial controller.
- Processing with no documented lawful basisdata protection officer.
- Confirmed accessibility barrier in checkoutaccessibility lead.
- Price or claim that fails transparency ruleslegal and compliance lead.
- Security incident or failed controlsecurity lead.
- Payment reconciliation break or chargeback spikepayments manager with finance.
Rule two leans on the ICO's storage and access guidance, which covers cookies and similar technologies under PECR. Its statutory maximum penalty is £17.5m or 4% of global annual turnover, whichever is higher.
See who owns what in a conversion change for how these roles divide on a live decision.
Prove the return with causal evidence
Raw conversion lift is not proof. Predeclare the outcome and the guardrail metrics, keep a control group, and log exposure. Then reconcile late data before anyone claims a result. Payment, refund and support costs belong in the same comparison, not in a footnote.
Rollout needs release evidence, alerting and a tested rollback. Exit needs export, configuration handover and deletion evidence.
Common questions
Do refunds and chargebacks need their own rows?
Yes. Separate authorisation, capture, refund and dispute, and record the provider entity and transaction condition. Providers typically charge £15 to £25 per chargeback dispute, plus the transaction amount if the case is lost.
Who can pause a conversion project?
The named owner of the stop rule that has been breached, not the person closest to the work. Each of the six rules carries one owner, so the pause is automatic.
Can I use published supplier prices in my budget?
Only as attributed inputs with an access date. Do not infer the purchased configuration, the actual invoice or a future renewal from a list price.
How do I avoid double counting VAT?
Fix the VAT basis on every row and keep it. Compare like with like, then let your accountant confirm recoverability and the tax point.
In this guide
- Ecommerce conversion cost guide: what a returned order costs under the 14-day refund rules, in poundsEcommerce conversion cost guide for England: refund timing, delivery refunds and VAT on a returned order, with a worked pound example for 1,000 orders.
- Seven conversion pricing structures measured on identical meters and whole-life costCompare conversion pricing structures by identical meters, included work, customer-state exposure, VAT fields and whole-life buyer cost clearly.
- Conversion ROI stays blank until the cost is whole and the uplift is causalCalculate ecommerce conversion ROI only from reviewed whole-life cost, causal incremental contribution, uncertainty and retained order states.
- Conversion changes: the work build quotes leave outEcommerce conversion hidden costs sit outside the build quote: seven merchant tasks a store change creates, what triggers each and the evidence to keep.
