Cart and checkout

• Cart (/shop/cart) lists each product with its photo, options, unit price, and line total. Quantities can be changed or removed. The subtotal follows the catalog tax display, and checkout stays closed until every line can be sold. Product pages and the cart only show a stock count when 5 or fewer are left.
• Checkout (/shop/checkout) collects contact, shipping, and billing details, then prices delivery, tax, and discounts. Country lists follow the selling and shipping countries. Guest checkout closes when the shop requires an account.
• Signed-in shoppers start with their account email, name, phone, and last billing and shipping addresses, all editable. Placing an order saves those details to the customer record linked to their account, and a first order gives them the Customer role.
• Placing an order stores it as Awaiting payment, reserves stock, and emails Order confirmed to the customer and New order to the store.
• Failed payments keep the cart. If a Mollie payment fails, is cancelled, or expires, the customer returns to checkout with their items, a message explaining why, and a different method preselected. Retrying updates the same order instead of creating a new one.

Cart and checkout routes are rate limited per IP: adding or updating a cart line allows 30 requests a minute, and checkout and the catalog allow 60.

• Create an account at checkout. Shoppers who are not signed in can choose a password with their order. It is required for a subscription and in shops without guest checkout. An email that already has an account is asked to sign in.
• Retry-safe. Each checkout submission carries a key, so submitting twice after a lost connection places one order.
• Clear errors. Required fields are marked, a refused value is explained under its field and read out by screen readers, and the cursor moves to the first field to fix.
• Free orders skip payment. When an order, and every renewal of a subscription in it, costs nothing, checkout hides the payment choices and the order is paid at once.
• VAT number. When invoices are on, business buyers can add a VAT number, printed on their invoice.