diff --git a/development.ini b/development.ini
index e209f09..631696b 100644
--- a/development.ini
+++ b/development.ini
@@ -53,6 +53,10 @@ app.bucket.secure_uploads.access_key = ${MPS_APP_SECURE_UPLOADS_ACCESS_KEY}
 app.bucket.secure_uploads.secret_key = ${MPS_APP_SECURE_UPLOADS_SECRET_KEY}
 
 
+# stripe test mode is enabled for development & disabled by default.
+app.stripe.test_mode = True
+
+
 # set this to the path of your private DKIM key.
 # reference: https://russell.ballestrini.net/quickstart-to-dkim-signed-email-with-python/
 #app.email.dkim_private_key_path = ${MPS_APP_DKIM_PRIVATE_KEY_PATH}
diff --git a/make_post_sell/views/shop.py b/make_post_sell/views/shop.py
index e63e92b..62fb309 100644
--- a/make_post_sell/views/shop.py
+++ b/make_post_sell/views/shop.py
@@ -387,6 +387,7 @@ def shop_settings(request):
         "plausible_domain_name", shop.plausible_domain_name or ""
     ).strip()
 
+    stripe_test_mode = request.app.get("stripe.test_mode", False)
     stripe_public_api_key = request.params.get(
         "stripe_public_api_key", shop.stripe_public_api_key
     )
@@ -505,8 +506,14 @@ def shop_settings(request):
 
         if stripe_public_api_key != shop.stripe_public_api_key:
             if stripe_public_api_key.startswith("pk_"):
-                shop.stripe_public_api_key = stripe_public_api_key
-                msg = ("You set the shop's stripe_public_api_key.", "success")
+                if not stripe_test_mode and "_test_" in stripe_public_api_key:
+                    msg = (
+                        "Test Stripe keys are not allowed. Please create a test shop at test.makepostsell.com.",
+                        "error",
+                    )
+                else:
+                    shop.stripe_public_api_key = stripe_public_api_key
+                    msg = ("You set the shop's stripe_public_api_key.", "success")
             else:
                 msg = (
                     "The shop's stripe_public_api_key must start with 'pk_'.",
@@ -516,8 +523,14 @@ def shop_settings(request):
 
         if stripe_secret_api_key != shop.stripe_secret_api_key:
             if stripe_secret_api_key.startswith("sk_"):
-                shop.stripe_secret_api_key = stripe_secret_api_key
-                msg = ("You set the shop's stripe_secret_api_key.", "success")
+                if not stripe_test_mode and "_test_" in stripe_secret_api_key:
+                    msg = (
+                        "Test Stripe keys are not allowed. Please create a test shop at test.makepostsell.com.",
+                        "error",
+                    )
+                else:
+                    shop.stripe_secret_api_key = stripe_secret_api_key
+                    msg = ("You set the shop's stripe_secret_api_key.", "success")
             else:
                 msg = (
                     "The shop's stripe_secret_api_key must start with 'sk_'.",
diff --git a/test.ini b/test.ini
index 26888c8..213a9f2 100644
--- a/test.ini
+++ b/test.ini
@@ -27,6 +27,9 @@ app.bucket.secure_uploads.get_endpoint = https://plan-period-files.nyc3.digitalo
 app.bucket.secure_uploads.access_key = ${MPS_APP_SECURE_UPLOADS_ACCESS_KEY}
 app.bucket.secure_uploads.secret_key = ${MPS_APP_SECURE_UPLOADS_SECRET_KEY}
 
+# stripe test mode is enabled for development & disabled by default.
+app.stripe.test_mode = True
+
 [pshell]
 setup = make_post_sell.scripts.pshell.setup