diff --git a/backend/composer.json b/backend/composer.json
index cadf49560..e078290ae 100644
--- a/backend/composer.json
+++ b/backend/composer.json
@@ -27,7 +27,7 @@
     "cebe/markdown": "^1.2",
     "yiisoft/yii2-httpclient": "^2.0",
     "kartik-v/yii2-tabs-x": "@dev",
-    "stripe/stripe-php": "^20.0",
+    "stripe/stripe-php": "^21.0",
     "sleifer/yii2-autocomplete-ajax": "dev-master",
     "ezyang/htmlpurifier": "^4.18",
     "yiisoft/yii2-bootstrap5": "^2.0",
diff --git a/backend/composer.lock b/backend/composer.lock
index 1686432c4..bd2c703bf 100644
--- a/backend/composer.lock
+++ b/backend/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "a8b734a3d5d2e5ded3e7dd804dd2cdc9",
+    "content-hash": "5b79e72ca375a3c094d98c520b9c7849",
     "packages": [
         {
             "name": "beluga-php/docker-php",
@@ -2780,16 +2780,16 @@
         },
         {
             "name": "stripe/stripe-php",
-            "version": "v20.3.0",
+            "version": "v21.0.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/stripe/stripe-php.git",
-                "reference": "266f0b05890172184cca66a0688abaf1a96b08d8"
+                "reference": "0498d20d0c33490c38df956dd7cef49b3a2ad6f0"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/stripe/stripe-php/zipball/266f0b05890172184cca66a0688abaf1a96b08d8",
-                "reference": "266f0b05890172184cca66a0688abaf1a96b08d8",
+                "url": "https://api.github.com/repos/stripe/stripe-php/zipball/0498d20d0c33490c38df956dd7cef49b3a2ad6f0",
+                "reference": "0498d20d0c33490c38df956dd7cef49b3a2ad6f0",
                 "shasum": ""
             },
             "require": {
@@ -2836,9 +2836,9 @@
             ],
             "support": {
                 "issues": "https://github.com/stripe/stripe-php/issues",
-                "source": "https://github.com/stripe/stripe-php/tree/v20.3.0"
+                "source": "https://github.com/stripe/stripe-php/tree/v21.0.0"
             },
-            "time": "2026-06-24T22:45:28+00:00"
+            "time": "2026-07-16T00:34:23+00:00"
         },
         {
             "name": "symfony/deprecation-contracts",