Your customer
Sees
Your brand, your products, your domain for the entire checkout.
Does not
See the payment store, its catalogue, or any redirect.
Platform
Your sales store keeps your brand, your catalogue and your customers. A second WooCommerce store on its own domain holds the merchant account and a plain, processor-friendly catalogue that a reviewer can browse and test-buy. TandemPay connects the two so the customer experience stays on your side and the audit surface stays on the other.
What your customer sees
Your order
Embedded · payment store
What a reviewer sees
Cotton tote
$64.00
Ceramic mug
$38.00
Perspectives
Your customer
Your brand, your products, your domain for the entire checkout.
See the payment store, its catalogue, or any redirect.
Your processor
The payment store on the merchant account: a normal WooCommerce shop with policy pages and a catalogue they underwrite.
See your sales catalogue, your main domain, or a redirect from it.
You
Fulfilment orders on Site A with real line items. Payment records on Site B with mapped products. Both totals match.
Run payments on the store that holds your flagged catalogue.
The architecture
Your domain, your products, your shipping and tax rules. The payment fields are embedded from the payment store, so the URL bar never changes.
Your processor's merchant account lives there. The charge is recorded against a mapped stand-in product with a clean descriptor.
Your store receives the order with the real line items, the real customer and the real totals, ready to pick and ship.
Payment history stays where the processor expects it. Fulfilment history stays where your operation needs it. Totals reconcile across both.
What you install
Site A, your sales store
Embeds the payment form at checkout, captures contact and shipping, creates the fulfilment order, and sends the customer their confirmation from your brand.
Site B, your payment store
Hosts the embedded checkout, maps products from Site A, applies shipping and discounts, captures the card through your processor, and records the payment-store order.
Capabilities
Payment fields load inside your checkout page in an iframe. The customer never navigates away from your domain.
Each Site A SKU maps to a stand-in product on Site B. Totals reconcile, including shipping and coupon codes applied on Site A.
When payment clears, a fulfilment order is created on Site A with your real line items, ready to pick and ship.
Cross-site checkout works without leaking cookies or referrer data to your processor. Built for modern browser privacy rules.
Site A is the source of truth for shipping rules and coupon codes. Site B mirrors the total before capture.
Third-party gateway rules on Site B, such as daily volume caps, apply to iframe orders the same way they apply to native checkout.
Requirements
The architecture only works if the payment store is built properly. That is what the playbook is for.