Checkout & Payment UI Optimization Agent

=== CHECKOUT & PAYMENT UI OPTIMIZATION AUDIT ===

Project
NorthPeak Commerce Checkout

Primary Conversion
Completed paid order

Platforms
Responsive web, mobile web, iOS, and Android

=== EXECUTIVE SUMMARY ===

The checkout supports the required transaction steps, but several interface decisions create avoidable uncertainty and abandonment risk.

The highest-priority problems are

1. Shipping costs appear too late.
2. Guest checkout is visually subordinate.
3. Mobile users lose access to the order summary.
4. Discount entry receives excessive prominence.
5. Card validation happens too late.
6. Declines use one generic message.
7. Payment submission lacks visible duplicate prevention.
8. Timeout recovery can remove cart context.
9. Subscription renewal terms are incomplete.
10. Confirmation lacks delivery guidance.
11. Mobile keyboard behavior obstructs payment.
12. Analytics cannot distinguish payment failure categories.

Recommended checkout sequence

Cart Review
→ Contact
→ Shipping Address
→ Shipping Method
→ Payment Method
→ Billing Details When Required
→ Final Review
→ Payment Processing
→ Confirmation

=== CART REVIEW AUDIT ===

Observed

• Product images are visible.
• Variant labels are small.
• Quantity changes update totals slowly.
• Shipping is shown as “Calculated Later.”
• The mobile order summary collapses automatically.
• Remove and Save for Later are visually similar.

Recommendations

• Make product name, variant, quantity, and line total easy to verify.
• Show the current shipping calculation state explicitly.
• Keep a visible mobile order-summary trigger with item count and current total.
• Preserve user-selected quantity during update failures.
• Separate Remove from Save for Later.
• Confirm inventory changes before payment submission.

Priority
High

=== PRICING TRANSPARENCY ===

Required summary

Subtotal
Verified cart subtotal

Discount
Show only when applied

Shipping
Calculated after destination or shown as a verified estimate

Tax
Calculated according to the verified tax service

Gift Card
Show applied value

Store Credit
Show applied value

Total Due Now
Prominent

Future Charge
Required for subscription products

Do not use “Free Shipping” unless the eligibility rule is currently satisfied.

When totals change

• identify the changed line
• show the previous and current total where useful
• explain the reason
• require review before payment when the change is material

=== GUEST CHECKOUT ===

Observed
Guest checkout appears as a small text link below account login.

Risk
Users may believe an account is required.

Recommendation
Present Guest Checkout and Sign In as parallel entry options.

Primary guest message
Continue without creating an account.

Post-purchase account creation
Offer account creation after confirmation using the verified order email.

Do not

• force password creation before payment
• hide guest checkout
• imply that guest orders receive weaker fulfillment
• require marketing consent

=== SHIPPING FLOW ===

Recommended order

1. Delivery country
2. Shipping address
3. Address validation where supported
4. Shipping methods
5. Delivery estimate
6. Pickup option where available

Required states

• loading
• available
• unavailable
• address incomplete
• unsupported destination
• service error
• selected
• price changed

Shipping method
Show name, price, delivery estimate, restrictions, and selected state.

Do not invent delivery dates.

=== BILLING FLOW ===

Default
Billing address is the same as shipping.

Display the separate billing form only when:

• the user disables same-as-shipping
• the selected payment method requires it
• regional requirements require it

Business tax fields
Show only in relevant markets and explain why they are required.

=== PAYMENT-METHOD HIERARCHY ===

Mobile priority

1. Eligible native wallet
2. Saved verified method
3. Card
4. PayPal
5. Regional methods
6. Buy now, pay later where eligible
7. Gift card and store credit

The exact order should reflect eligibility, user context, market, and verified business priorities.

Do not show unavailable methods as selectable.

=== WALLET STRATEGY ===

Apple Pay
Show only on supported Apple contexts.

Google Pay
Show only on supported contexts.

Wallet action
Express payment with clear total context.

After wallet return
Restore the checkout state and show the verified transaction result.

Do not

• show both wallets when one is unavailable
• duplicate shipping collection unnecessarily
• claim payment completion before provider confirmation

=== DISCOUNT-CODE OPTIMIZATION ===

Current issue
The expanded discount field dominates the mobile checkout.

Recommendation
Use a collapsed “Add discount or gift card” control.

After expansion

• label the field
• support Apply
• show loading
• show success
• show invalid
• show expired
• show restriction
• support removal

Do not clear the code silently after an error.

=== TRUST SYSTEM ===

Place trust near the payment decision.

Approved trust content may include

• verified secure-payment provider
• verified return policy
• support access
• delivery information
• approved payment-method logos
• verified review evidence

Do not use

• fake security seals
• unsupported encryption claims
• generic “100% Safe” claims
• unverified guarantees
• false countdowns

=== VALIDATION STRATEGY ===

Validate progressively without interrupting normal input.

Contact
Validate email format after sufficient input.

Address
Validate required fields and supported formats.

Card
Validate number structure, expiration, security code, and required billing data.

Discount
Validate after Apply.

Final submission
Validate complete checkout state.

Focus behavior
Move focus to an error summary or the first invalid field according to the approved accessibility pattern.

Preserve valid data.

=== PAYMENT STATE MODEL ===

Idle
Payment has not started.

Validating
Checkout data is being checked.

Ready
Payment may be submitted.

Submitting
Submission is in progress.

Authentication Required
Additional provider or issuer authentication is required.

Processing
The result is pending.

Completed
Payment and order creation are confirmed.

Declined
The provider or issuer returned a verified decline.

Failed
A verified technical failure occurred.

Cancelled
The user or provider cancelled the payment flow.

Uncertain
The final transaction status is not confirmed.

Duplicate Prevented
A repeated submission was blocked.

=== DUPLICATE-PAYMENT PREVENTION ===

When payment is submitted

• disable repeated submission
• show processing status
• preserve an idempotent transaction reference
• prevent repeated taps
• preserve checkout context
• verify the final status before enabling retry

Given the user taps Pay repeatedly,
when the first valid submission is already active,
then additional submissions are blocked without creating another payment request.

=== DECLINE ARCHITECTURE ===

Generic decline
Payment was not approved.

Recommended action
Use another payment method or contact the payment provider.

Expired card
Update the expiration date or choose another payment method.

Authentication failure
Retry the verified authentication step or select another method.

Insufficient funds
Use provider-approved wording only.

Do not

• expose sensitive fraud rules
• blame the user
• claim an issuer reason that was not returned
• remove cart data

=== UNCERTAIN PAYMENT FLOW ===

Heading
Confirming Your Payment

Message
The final payment status has not been confirmed yet. Do not submit another payment while we check the transaction.

Required actions

• check order status
• check payment status
• preserve cart and checkout context
• provide a transaction reference
• prevent duplicate submission
• offer support after the verified waiting threshold
• show the final result when confirmed

Do not display “Payment Failed” unless failure is verified.

=== SUBSCRIPTION CHECKOUT ===

Required information

• plan name
• verified price
• currency
• billing cadence
• amount due now
• trial terms
• renewal date or rule
• future price
• included features
• usage limits
• cancellation access
• refund context

The final payment action should communicate the transaction accurately.

Example
Start Verified Trial

or:

Subscribe for Verified Price

Exact language depends on confirmed commercial terms.

=== ORDER CONFIRMATION ===

Required

• order number
• payment status
• purchased items
• amount
• currency
• delivery or access information
• receipt access
• support
• next action

Physical goods
Show delivery destination and verified delivery estimate.

Digital goods
Show access or download instructions.

Subscription
Show plan, status, cadence, and next verified billing event.

Booking
Show service, provider, date, time, timezone, location, and verified status.

Do not display confirmation before order creation and payment state are verified.

=== ABANDONED-CHECKOUT RECOVERY ===

Recovery requirements

• preserve cart contents
• preserve valid checkout progress where approved
• validate inventory
• validate price
• validate shipping
• validate discounts
• refresh expired payment sessions
• return users to the correct step

Recovery message
Explain when a price, item, discount, or delivery option changed.

Marketing recovery
Requires appropriate consent and frequency controls.

Do not use false urgency.

=== RESPONSIVE REQUIREMENTS ===

Desktop

• visible order summary
• clear step progress
• focused form width
• stable payment region

Tablet

• one or two columns according to width
• readable totals
• non-obstructive summary

Mobile

• single-column flow
• persistent summary access
• full-width primary action
• keyboard-safe payment button
• wallet prioritization
• no page-level horizontal scrolling
• no sticky element covering focused fields

Small Mobile

• wrapped labels
• compact product rows
• card-based totals
• no clipped prices

200% Zoom:

• reflow
• no overlap
• no inaccessible horizontal scrolling
• visible totals and actions

=== ACCESSIBILITY REQUIREMENTS ===

• Semantic form structure
• Persistent labels
• Accessible error summaries
• Field-level error associations
• Keyboard operation
• Visible focus
• Screen-reader payment-method names
• Accessible wallet buttons
• Non-color status communication
• Large touch targets
• Zoom and reflow
• Reduced motion
• Timeout warnings
• Dialog focus management
• Mobile keyboard support
• No claim of conformance without testing

=== ANALYTICS EVENT MAP ===

checkout_started

Properties

• cart_type
• platform
• market
• currency

shipping_completed

Properties

• shipping_method_category
• market

payment_method_selected

Properties

• payment_method_category
• wallet_eligible

payment_submitted

Properties

• method_category
• cart_value_bucket

payment_declined

Properties

• approved_reason_category
• method_category

payment_uncertain

Properties

• provider_stage
• method_category

checkout_completed

Properties

• order_type
• currency
• cart_value_bucket

Privacy
Do not record card numbers, security codes, bank details, passwords, payment tokens, full billing addresses, or sensitive transaction content.

=== EXPERIMENT ROADMAP ===

Experiment 1:
Guest Checkout Prominence

Hypothesis
Presenting guest checkout as a primary option will reduce checkout-entry abandonment.

Primary Metric
Completed purchases

Guardrail
Account-linked order rate

Experiment 2:
Mobile Order Summary

Hypothesis
Keeping total and item count visible will reduce price-related abandonment.

Primary Metric
Payment submissions

Guardrail
Back-navigation rate

Experiment 3:
Wallet-First Mobile Layout

Hypothesis
Prioritizing eligible native wallets will reduce mobile payment friction.

Primary Metric
Completed mobile payments

Guardrail
Payment failure rate

Experiment 4:
Collapsed Discount Field

Hypothesis
Reducing discount-field prominence will improve progression without reducing legitimate discount use.

Primary Metric
Checkout completion

Guardrail
Successful discount application

=== DEVELOPER HANDOFF ===

Required modules

• CheckoutShell
• CartReview
• ContactForm
• ShippingAddress
• ShippingMethodSelector
• BillingAddress
• PaymentMethodSelector
• CardForm
• WalletActions
• DiscountControl
• OrderSummary
• TrustPanel
• PaymentStatus
• CheckoutErrorSummary
• ConfirmationPage
• RecoveryPage

Required state domains

• cart
• customer
• shipping
• billing
• discounts
• payment
• inventory
• totals
• subscription
• booking
• recovery
• analytics

=== ACCEPTANCE CRITERIA ===

Guest Checkout

Given a user is not signed in,
when checkout begins,
then Guest Checkout is clearly available without creating an account.

Pricing

Given shipping, tax, or discounts update,
when the total changes,
then the updated line item and total are visible before payment.

Duplicate Prevention

Given a payment submission is active,
when the user taps the payment action again,
then another payment request is not created.

Uncertain Payment

Given the provider result is inconclusive,
when the user returns,
then the interface shows an uncertain state, preserves context, and prevents unsafe resubmission.

Card Decline

Given a verified decline occurs,
when the error is shown,
then the user receives a safe recovery action without losing valid checkout data.

Mobile Keyboard

Given a mobile keyboard is open,
when the user completes the final payment field,
then the payment action remains reachable and does not cover content.

Confirmation

Given payment and order creation are confirmed,
when the confirmation screen appears,
then the order reference, total, purchased items, delivery or access details, and support path are available.

=== REGRESSION TEST MATRIX ===

Checkout Types

• Physical Product
• Digital Product
• Subscription
• Booking
• Marketplace
• Mixed Cart

Users

• Guest
• Signed In
• Returning Customer
• New Customer

Payments

• Card
• Saved Card
• Apple Pay
• Google Pay
• PayPal
• Gift Card
• Store Credit
• Buy Now, Pay Later

States

• Ready
• Validating
• Processing
• Authentication Required
• Completed
• Declined
• Failed
• Cancelled
• Uncertain
• Duplicate Prevented

Responsive

• Small Mobile
• Standard Mobile
• Tablet
• Laptop
• Desktop
• Short Viewport
• 200% Zoom

Localization

• English
• German
• French
• Spanish
• Right-to-Left Test
• Long Address
• Long Product Name
• Large Currency Value

=== QA CHECKLIST ===

Cart

• Verify products.
• Verify variants.
• Verify quantities.
• Verify prices.
• Verify cart persistence.

Totals

• Verify subtotal.
• Verify discounts.
• Verify shipping.
• Verify taxes.
• Verify fees.
• Verify credits.
• Verify total due now.
• Verify future charges.

Shipping

• Verify address.
• Verify methods.
• Verify delivery estimates.
• Verify unsupported destinations.
• Verify errors.

Payment

• Verify eligibility.
• Verify method order.
• Verify card validation.
• Verify wallets.
• Verify authentication.
• Verify duplicate prevention.
• Verify declines.
• Verify uncertain states.

Subscription

• Verify price.
• Verify cadence.
• Verify trial.
• Verify renewal.
• Verify limitations.
• Verify cancellation.

Confirmation

• Verify order number.
• Verify payment state.
• Verify purchased items.
• Verify total.
• Verify delivery or access.
• Verify receipt.
• Verify support.

Accessibility

• Verify labels.
• Verify errors.
• Verify focus.
• Verify keyboard navigation.
• Verify screen readers.
• Verify touch targets.
• Verify zoom.
• Verify reflow.
• Verify non-color states.
• Verify mobile keyboard behavior.

=== RISKS ===

Risk
Shipping or taxes create a late price surprise.

Mitigation
Show available estimates early and explain recalculation.

Risk
Users submit duplicate payments.

Mitigation
Use submission locking, idempotency, status verification, and safe retries.

Risk
An uncertain payment is presented as failed.

Mitigation
Use a distinct uncertain state and backend reconciliation.

Risk
Subscription terms are unclear.

Mitigation
Show verified current and future charges, cadence, renewal, limitations, and cancellation access.

Risk
A recovery link restores an invalid cart.

Mitigation
Revalidate price, stock, shipping, discount, and payment session before resuming.

Risk
Analytics capture sensitive payment data.

Mitigation
Use approved categories and exclude payment credentials and private transaction content.

=== KNOWN LIMITATIONS ===

• Payment behavior requires provider and backend verification.
• Tax and shipping require authoritative services.
• Inventory requires real-time validation.
• Subscription behavior requires commercial and platform validation.
• Refunds and cancellations require verified policies.
• Accessibility requires implementation testing.
• Localization requires regional review.
• Experiment conclusions require sufficient traffic.
• The audit does not guarantee conversion, revenue, payment success, fraud reduction, or legal compliance.

=== FINAL INTEGRITY NOTE ===

All prices, taxes, fees, discounts, inventory states, shipping promises, payment outcomes, subscription terms, trial conditions, renewal dates, proration rules, refunds, booking states, marketplace responsibilities, and legal disclosures must be verified before implementation.

Never describe a payment as completed, failed, refunded, cancelled, or not charged unless the verified system state confirms that outcome.

The checkout architecture is designed to improve clarity, payment confidence, accessibility, recovery, and conversion readiness. It does not guarantee higher sales, lower abandonment, payment approval, fraud reduction, or legal compliance.