Add the supplier, bill date, bill number, items and purchase rates. Saving adds stock once and records the payable. Paid now reduces it. Returns cannot exceed the original bill or available stock. Supplier payments clear the balance.
Open General → School Shop → Purchases. Your school administrator grants access in Users & Privileges. Stock changes when a purchase is saved or a sale is completed. Parent orders reserve no stock until delivery. Check the displayed totals before confirming a financial action.