diff --git a/app/(tabs)/beneficiaries/[id]/index.tsx b/app/(tabs)/beneficiaries/[id]/index.tsx
index b83daee..dea4e44 100644
--- a/app/(tabs)/beneficiaries/[id]/index.tsx
+++ b/app/(tabs)/beneficiaries/[id]/index.tsx
@@ -43,6 +43,7 @@ import {
 } from '@/services/BeneficiaryDetailController';
 import { BeneficiaryMenu } from '@/components/ui/BeneficiaryMenu';
 import { ImageLightbox } from '@/components/ImageLightbox';
+import { bustImageCache } from '@/utils/imageUtils';
 
 // WebView Dashboard URL - opens specific deployment directly
 const getDashboardUrl = (deploymentId?: number) => {
@@ -298,7 +299,8 @@ export default function BeneficiaryDetailScreen() {
 
       setIsEditModalVisible(false);
       toast.success('Saved', isCustodian ? 'Profile updated successfully' : 'Nickname saved');
-      loadBeneficiary(false);
+      // Reload to get updated data with fresh avatar URL (cache-busting timestamp will be applied)
+      await loadBeneficiary(false);
     } catch (err) {
       toast.error('Error', 'Failed to save changes.');
     } finally {
@@ -389,7 +391,7 @@ export default function BeneficiaryDetailScreen() {
             disabled={!beneficiary.avatar || beneficiary.avatar.trim() === '' || beneficiary.avatar.includes('placeholder')}
           >
             {beneficiary.avatar && beneficiary.avatar.trim() !== '' && !beneficiary.avatar.includes('placeholder') ? (
-              <Image source={{ uri: beneficiary.avatar }} style={styles.headerAvatarImage} />
+              <Image source={{ uri: bustImageCache(beneficiary.avatar) || undefined }} style={styles.headerAvatarImage} />
             ) : (
               <View style={styles.headerAvatar}>
                 <Text style={styles.headerAvatarText}>
@@ -526,7 +528,7 @@ export default function BeneficiaryDetailScreen() {
                     disabled={isSavingEdit}
                   >
                     {editForm.avatar ? (
-                      <Image source={{ uri: editForm.avatar }} style={styles.avatarPickerImage} />
+                      <Image source={{ uri: bustImageCache(editForm.avatar) || undefined }} style={styles.avatarPickerImage} />
                     ) : (
                       <View style={styles.avatarPickerPlaceholder}>
                         <Ionicons name="camera" size={32} color={AppColors.textMuted} />
@@ -625,7 +627,7 @@ export default function BeneficiaryDetailScreen() {
       {/* Avatar Lightbox */}
       <ImageLightbox
         visible={lightboxVisible}
-        imageUri={beneficiary?.avatar || null}
+        imageUri={bustImageCache(beneficiary?.avatar)}
         onClose={() => setLightboxVisible(false)}
       />
     </SafeAreaView>
diff --git a/app/(tabs)/index.tsx b/app/(tabs)/index.tsx
index 956aed2..40125d9 100644
--- a/app/(tabs)/index.tsx
+++ b/app/(tabs)/index.tsx
@@ -27,6 +27,7 @@ import {
 } from '@/constants/theme';
 import type { Beneficiary } from '@/types';
 import { isSubscriptionActive } from '@/services/subscription';
+import { bustImageCache } from '@/utils/imageUtils';
 
 // Beneficiary card with equipment status support
 interface BeneficiaryCardProps {
@@ -115,7 +116,7 @@ function BeneficiaryCard({ beneficiary, onPress, onActivate }: BeneficiaryCardPr
       {/* Avatar */}
       <View style={styles.avatarWrapper}>
         {hasValidAvatar ? (
-          <Image source={{ uri: beneficiary.avatar }} style={styles.avatarImage} />
+          <Image source={{ uri: bustImageCache(beneficiary.avatar) || undefined }} style={styles.avatarImage} />
         ) : (
           <View style={[styles.avatar, hasNoSubscription && styles.avatarNoSubscription]}>
             <Text style={[styles.avatarText, hasNoSubscription && styles.avatarTextNoSubscription]}>
diff --git a/utils/__tests__/imageUtils.test.ts b/utils/__tests__/imageUtils.test.ts
new file mode 100644
index 0000000..11a0eac
--- /dev/null
+++ b/utils/__tests__/imageUtils.test.ts
@@ -0,0 +1,65 @@
+import { bustImageCache } from '../imageUtils';
+
+describe('bustImageCache', () => {
+  it('should add cache-busting parameter to HTTP URLs', () => {
+    const url = 'https://example.com/avatar.jpg';
+    const result = bustImageCache(url, 1234567890);
+    expect(result).toBe('https://example.com/avatar.jpg?t=1234567890');
+  });
+
+  it('should add cache-busting parameter to URLs with existing query params', () => {
+    const url = 'https://example.com/avatar.jpg?size=large';
+    const result = bustImageCache(url, 1234567890);
+    expect(result).toBe('https://example.com/avatar.jpg?size=large&t=1234567890');
+  });
+
+  it('should not add cache-busting to file:// URIs', () => {
+    const uri = 'file:///path/to/local/image.jpg';
+    const result = bustImageCache(uri);
+    expect(result).toBe(uri);
+  });
+
+  it('should not add cache-busting to data URIs', () => {
+    const dataUri = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA';
+    const result = bustImageCache(dataUri);
+    expect(result).toBe(dataUri);
+  });
+
+  it('should not add cache-busting to placeholder images', () => {
+    const placeholderUrl = 'https://example.com/placeholder.png';
+    const result = bustImageCache(placeholderUrl);
+    expect(result).toBe(placeholderUrl);
+  });
+
+  it('should return null for null input', () => {
+    const result = bustImageCache(null);
+    expect(result).toBeNull();
+  });
+
+  it('should return null for undefined input', () => {
+    const result = bustImageCache(undefined);
+    expect(result).toBeNull();
+  });
+
+  it('should return null for empty string', () => {
+    const result = bustImageCache('');
+    expect(result).toBeNull();
+  });
+
+  it('should use current timestamp when not provided', () => {
+    const url = 'https://example.com/avatar.jpg';
+    const beforeTimestamp = Date.now();
+    const result = bustImageCache(url);
+    const afterTimestamp = Date.now();
+
+    // Extract timestamp from result
+    const match = result?.match(/t=(\d+)/);
+    expect(match).toBeTruthy();
+
+    if (match) {
+      const timestamp = parseInt(match[1], 10);
+      expect(timestamp).toBeGreaterThanOrEqual(beforeTimestamp);
+      expect(timestamp).toBeLessThanOrEqual(afterTimestamp);
+    }
+  });
+});
diff --git a/utils/imageUtils.ts b/utils/imageUtils.ts
index e8b4b63..b801866 100644
--- a/utils/imageUtils.ts
+++ b/utils/imageUtils.ts
@@ -51,3 +51,36 @@ export async function optimizeImage(
     return uri;
   }
 }
+
+/**
+ * Add cache-busting query parameter to image URL
+ * Prevents browsers and React Native Image from caching old versions
+ *
+ * @param uri - Image URI (can be http, https, or file://)
+ * @param timestamp - Optional timestamp (defaults to current time)
+ * @returns URI with cache-busting parameter
+ */
+export function bustImageCache(uri: string | null | undefined, timestamp?: number): string | null {
+  if (!uri || uri.trim() === '') {
+    return null;
+  }
+
+  // Don't add cache buster to local file URIs (file://)
+  if (uri.startsWith('file://')) {
+    return uri;
+  }
+
+  // Don't add cache buster to data URIs
+  if (uri.startsWith('data:')) {
+    return uri;
+  }
+
+  // Don't add cache buster to placeholder images
+  if (uri.includes('placeholder')) {
+    return uri;
+  }
+
+  const cacheBuster = timestamp || Date.now();
+  const separator = uri.includes('?') ? '&' : '?';
+  return `${uri}${separator}t=${cacheBuster}`;
+}