diff --git a/repositories/orderRepository.go b/repositories/orderRepository.go
index 90149d1..8f6c5bc 100644
--- a/repositories/orderRepository.go
+++ b/repositories/orderRepository.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"nearle/models"
+	"sort"
 	"strings"
 	"time"
 
@@ -1130,6 +1131,49 @@ func (r *orderRepository) CreateOrder(data models.Orders) (models.Orders, error)
 		locID = data.Applocationid
 	}
 
+	// 🛠️ Step 0: Lock every (tenantid, locationid, productid) row this order
+	// touches before checking availability. Without this, two concurrent
+	// orders for the same product can both read "stock available" before
+	// either commits its deduction, oversell the item, and drive stock
+	// negative. Locking productlocations — the row the stock computation is
+	// already keyed against — serializes conflicting orders instead.
+	//
+	// Locks are acquired in a fixed (productid, locationid) order so that
+	// two orders sharing overlapping products always contend for them in
+	// the same sequence, avoiding a lock-ordering deadlock between the two
+	// transactions (as opposed to just making each individually block).
+	type lockTarget struct {
+		productid  int
+		locationid int
+	}
+	seen := make(map[lockTarget]bool)
+	locks := make([]lockTarget, 0, len(data.Items))
+	for _, item := range data.Items {
+		itemLocID := item.Locationid
+		if itemLocID == 0 {
+			itemLocID = locID
+		}
+		lt := lockTarget{productid: item.Productid, locationid: itemLocID}
+		if !seen[lt] {
+			seen[lt] = true
+			locks = append(locks, lt)
+		}
+	}
+	sort.Slice(locks, func(a, b int) bool {
+		if locks[a].productid != locks[b].productid {
+			return locks[a].productid < locks[b].productid
+		}
+		return locks[a].locationid < locks[b].locationid
+	})
+	for _, lt := range locks {
+		var locked int
+		lockQuery := `SELECT productlocationid FROM productlocations WHERE tenantid = ? AND locationid = ? AND productid = ? FOR UPDATE`
+		if err := tx.Raw(lockQuery, data.Tenantid, lt.locationid, lt.productid).Scan(&locked).Error; err != nil {
+			tx.Rollback()
+			return models.Orders{}, fmt.Errorf("failed to lock stock for product %d: %w", lt.productid, err)
+		}
+	}
+
 	// 🛠️ Step 1: Pre-validate stock availability for all items before placing order
 	for _, item := range data.Items {
 		itemLocID := item.Locationid