A supplier is anyone you buy from. Stokk creates a supplier row for each vendor synced from your ERP and gives you a per-supplier page for planning and ordering.
Open Purchasing → Suppliers. You'll see one row per supplier with a few quick stats: SKU count, value on hand, lead time, and the most recent Morning Brief decision.
Click a row to open the supplier page. The layout is a single scroll, not tabs:
New suppliers come in through ERP sync; you shouldn't normally need to create one manually. If a supplier exists in Stokk before the ERP, it's typically a sync ordering issue rather than something to fix in the UI.
Deactivating a supplier in Settings → Suppliers takes them out of replenishment and order suggestions. You can do this even when the supplier is still open in your ERP, which is the usual situation: people stop buying from a vendor long before anyone blocks them in the ERP, if they ever do.
Stokk normally mirrors whatever the ERP says about a supplier being open or closed, and re-checks it on every sync. Once you set the status yourself, your choice wins and the sync stops overwriting it. The supplier list marks those with set in Stokkso you can tell your decisions apart from the ERP's.
To hand control back, use Follow ERP next to the supplier. From the next sync onward, the ERP decides again.