Marketplace is the module for the business that runs the market rather than trading in it: other businesses — your sellers — offer their goods through your marketplace, buyers buy, the money lands with you, you keep a commission, and the rest becomes money you owe the seller. This chapter is written from the operator's chair: onboarding sellers, keeping their listings, writing the commission rules, recording orders, and paying sellers what they are owed.
One idea organises the whole module, and it is worth stating before any form: a seller is a supplier wearing a second hat. The business that sells through your marketplace is recorded once, as a supplier (Chapter 4), with the marketplace fields switched on. That is not a shortcut — it is the truth of the money. What you owe a seller for a marketplace order is a payable like any other, so it lives on the same supplier balance, is paid through the same payment flow, and reads on the same supplier statement. One record, one balance, no second ledger to reconcile.
(The other hat exists too: when your business sells through someone else's marketplace, your own sales documents carry the channel and your receipts carry the fee — that story is told in Chapter 3, §3.5 and §3.6. This chapter never leaves the operator's chair.)