diff --git a/marketplace/src/components/ProductCard.tsx b/marketplace/src/components/ProductCard.tsx
index efd4145..06fb799 100644
--- a/marketplace/src/components/ProductCard.tsx
+++ b/marketplace/src/components/ProductCard.tsx
@@ -1,4 +1,5 @@
 import { ProductWithDistance } from '../types/product'
+import { formatCents } from '../utils/format'
 
 interface ProductCardProps {
     product: ProductWithDistance
@@ -38,7 +39,7 @@ export const ProductCard = ({ product, onAddToCart }: ProductCardProps) => {
 
                 <div className="flex justify-between items-end mt-4">
                     <div className="text-2xl font-bold text-green-600">
-                        R$ {(product.price_cents / 100).toFixed(2).replace('.', ',')}
+                        {formatCents(product.price_cents)}
                     </div>
                     <button
                         onClick={() => onAddToCart(product)}
diff --git a/marketplace/src/pages/Cart.tsx b/marketplace/src/pages/Cart.tsx
index 00e17c7..422207b 100644
--- a/marketplace/src/pages/Cart.tsx
+++ b/marketplace/src/pages/Cart.tsx
@@ -1,5 +1,6 @@
 import { Shell } from '../layouts/Shell'
 import { selectGroupedCart, selectCartSummary, useCartStore } from '../stores/cartStore'
+import { formatCurrency } from '../utils/format'
 
 export function CartPage() {
   const items = useCartStore((state) => state.items)
@@ -22,7 +23,7 @@ export function CartPage() {
           </div>
           <div className="text-right">
             <p className="text-sm text-gray-600">Itens: {summary.totalItems}</p>
-            <p className="text-lg font-semibold text-medicalBlue">R$ {summary.totalValue.toFixed(2)}</p>
+            <p className="text-lg font-semibold text-medicalBlue">R$ {formatCurrency(summary.totalValue)}</p>
           </div>
         </div>
         {items.length === 0 ? (
@@ -58,7 +59,7 @@ export function CartPage() {
                     </div>
                     <div className="text-right">
                       <p className="text-xs text-gray-500">Preço</p>
-                      <p className="font-semibold text-medicalBlue">R$ {item.unitPrice.toFixed(2)}</p>
+                      <p className="font-semibold text-medicalBlue">R$ {formatCurrency(item.unitPrice)}</p>
                     </div>
                     <div className="flex items-center justify-end gap-2">
                       <input
@@ -73,7 +74,7 @@ export function CartPage() {
                     <div className="text-right">
                       <p className="text-xs text-gray-500">Subtotal</p>
                       <p className="font-semibold text-gray-800">
-                        R$ {(item.quantity * item.unitPrice).toFixed(2)}
+                        R$ {formatCurrency(item.quantity * item.unitPrice)}
                       </p>
                       <button
                         className="text-xs text-red-500 hover:underline"
@@ -86,7 +87,7 @@ export function CartPage() {
                 ))}
                 <div className="flex items-center justify-between rounded bg-gray-100 px-3 py-2 text-sm">
                   <span className="font-semibold text-gray-700">Total do fornecedor</span>
-                  <span className="font-bold text-medicalBlue">R$ {group.total.toFixed(2)}</span>
+                  <span className="font-bold text-medicalBlue">R$ {formatCurrency(group.total)}</span>
                 </div>
               </div>
             </div>
@@ -109,3 +110,4 @@ export function CartPage() {
     </Shell>
   )
 }
+
diff --git a/marketplace/src/pages/Dashboard.tsx b/marketplace/src/pages/Dashboard.tsx
index a9a98be..218fbd4 100644
--- a/marketplace/src/pages/Dashboard.tsx
+++ b/marketplace/src/pages/Dashboard.tsx
@@ -3,6 +3,7 @@ import { FixedSizeList as List, ListChildComponentProps } from 'react-window'
 import { Product } from '../types/product'
 import { useCartStore } from '../stores/cartStore'
 import { Shell } from '../layouts/Shell'
+import { formatCents } from '../utils/format'
 
 // Mock data updated to match new Product interface
 const mockProducts: Product[] = Array.from({ length: 500 }).map((_, idx) => {
@@ -33,7 +34,7 @@ function DenseRow({ index, style, data }: ListChildComponentProps<Product[]>) {
       <div className="truncate text-gray-700">{product.description}</div>
       <div className="truncate text-gray-700">{product.batch}</div>
       <div className="truncate text-gray-700">{product.expires_at}</div>
-      <div className="text-right font-semibold text-medicalBlue">R$ {(product.price_cents / 100).toFixed(2)}</div>
+      <div className="text-right font-semibold text-medicalBlue">{formatCents(product.price_cents)}</div>
       <div className="col-span-2 flex items-center justify-end gap-2">
         <button
           className="rounded bg-healthGreen px-3 py-1 text-xs font-semibold text-white shadow-sm hover:opacity-90"
diff --git a/marketplace/src/pages/Inventory.tsx b/marketplace/src/pages/Inventory.tsx
index 92aaf6c..38bf7d8 100644
--- a/marketplace/src/pages/Inventory.tsx
+++ b/marketplace/src/pages/Inventory.tsx
@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react'
 import { Shell } from '../layouts/Shell'
 import { apiClient } from '../services/apiClient'
+import { formatCents } from '../utils/format'
 
 interface InventoryItem {
     product_id: string
@@ -124,7 +125,7 @@ export function InventoryPage() {
                                     </td>
                                     <td className="px-4 py-3 text-right text-sm font-semibold text-gray-800">{item.quantity}</td>
                                     <td className="px-4 py-3 text-right text-sm text-medicalBlue">
-                                        R$ {(item.price_cents / 100).toFixed(2)}
+                                        {formatCents(item.price_cents)}
                                     </td>
                                     <td className="px-4 py-3 text-center">
                                         <div className="flex justify-center gap-2">
diff --git a/marketplace/src/pages/Orders.tsx b/marketplace/src/pages/Orders.tsx
index ef09508..38b4dbb 100644
--- a/marketplace/src/pages/Orders.tsx
+++ b/marketplace/src/pages/Orders.tsx
@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react'
 import { Shell } from '../layouts/Shell'
 import { apiClient } from '../services/apiClient'
+import { formatCents } from '../utils/format'
 
 interface Order {
     id: string
@@ -50,7 +51,7 @@ export function OrdersPage() {
         }
     }
 
-    const formatCurrency = (cents: number) => `R$ ${(cents / 100).toFixed(2)}`
+    const formatCurrency = (cents: number | undefined | null) => formatCents(cents)
 
     return (
         <Shell>
diff --git a/marketplace/src/pages/SellerDashboard.tsx b/marketplace/src/pages/SellerDashboard.tsx
index 918f2cd..18b438c 100644
--- a/marketplace/src/pages/SellerDashboard.tsx
+++ b/marketplace/src/pages/SellerDashboard.tsx
@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react'
 import { Shell } from '../layouts/Shell'
 import { apiClient } from '../services/apiClient'
+import { formatCents } from '../utils/format'
 
 interface SellerDashboardData {
     seller_id: string
@@ -48,7 +49,7 @@ export function SellerDashboardPage() {
         }
     }
 
-    const formatCurrency = (cents: number) => `R$ ${(cents / 100).toFixed(2)}`
+    const formatCurrency = (cents: number | undefined | null) => formatCents(cents)
 
     return (
         <Shell>
diff --git a/marketplace/src/utils/format.ts b/marketplace/src/utils/format.ts
new file mode 100644
index 0000000..56e472a
--- /dev/null
+++ b/marketplace/src/utils/format.ts
@@ -0,0 +1,20 @@
+/**
+ * Safely format a numeric value as Brazilian currency (R$)
+ * Handles undefined, null, and NaN values gracefully
+ */
+export const formatCurrency = (value: number | undefined | null): string => {
+    if (value === undefined || value === null || isNaN(value)) {
+        return '0,00'
+    }
+    return value.toFixed(2).replace('.', ',')
+}
+
+/**
+ * Format cents to currency string
+ */
+export const formatCents = (cents: number | undefined | null): string => {
+    if (cents === undefined || cents === null || isNaN(cents)) {
+        return 'R$ 0,00'
+    }
+    return `R$ ${(cents / 100).toFixed(2).replace('.', ',')}`
+}