diff --git a/.env.example b/.env.example
index 89e85750..0774d263 100644
--- a/.env.example
+++ b/.env.example
@@ -21,3 +21,8 @@ TRUSTED_PROXIES="*"
 # Dompdf: keep false so untrusted HTML in PDF notes cannot trigger outbound requests (SSRF).
 # Set true only if you fully trust all PDF HTML and need remote images/CSS.
 DOMPDF_ENABLE_REMOTE=false
+
+# InvoiceShelf marketplace and updater base URL.
+# Defaults to https://invoiceshelf.com. Override to point at a local website
+# checkout for development:
+# INVOICESHELF_BASE_URL=http://invoiceshelf-website.test
diff --git a/config/invoiceshelf.php b/config/invoiceshelf.php
index fba7c1d3..60182c62 100644
--- a/config/invoiceshelf.php
+++ b/config/invoiceshelf.php
@@ -42,9 +42,16 @@ return [
     'min_sqlite_version' => '3.35.0',
 
     /*
-    * Marketplace url.
+    * Marketplace and updater base URL.
+    *
+    * The marketplace client (App\Services\Module\ModuleInstaller) and the
+    * updater (App\Services\Update\Updater) both build their HTTP client base
+    * URI from this value via App\Traits\SiteApi::getRemote(). Override via
+    * INVOICESHELF_BASE_URL in .env to point a self-hosted instance or local
+    * dev environment at a non-production marketplace (e.g. a local checkout
+    * of the invoiceshelf/website repo).
     */
-    'base_url' => 'https://invoiceshelf.com',
+    'base_url' => env('INVOICESHELF_BASE_URL', 'https://invoiceshelf.com'),
 
     /*
     * Paths protected from cleanup during updates.