diff --git a/.env.example b/.env.example
index f84708528ee5..76a3928a4063 100644
--- a/.env.example
+++ b/.env.example
@@ -5,20 +5,14 @@ APP_DEBUG=false
 
 APP_URL=http://localhost
 
-DB_CONNECTION=db-ninja-01
+DB_CONNECTION=mysql
 MULTI_DB_ENABLED=false
 
-DB_HOST1=localhost
-DB_DATABASE1=ninja
-DB_USERNAME1=ninja
-DB_PASSWORD1=ninja
-DB_PORT1=3306
-
-DB_HOST2=localhost
-DB_DATABASE2=ninja2
-DB_USERNAME2=ninja
-DB_PASSWORD2=ninja
-DB_PORT2=3306
+DB_HOST=localhost
+DB_DATABASE=ninja
+DB_USERNAME=ninja
+DB_PASSWORD=ninja
+DB_PORT=3306
 
 DEMO_MODE=false
 
diff --git a/app/Http/Controllers/SetupController.php b/app/Http/Controllers/SetupController.php
index b788f816bf0b..d726225f0cb7 100644
--- a/app/Http/Controllers/SetupController.php
+++ b/app/Http/Controllers/SetupController.php
@@ -109,11 +109,11 @@ class SetupController extends Controller
             'REQUIRE_HTTPS' => $request->input('https') ? 'true' : 'false',
             'APP_DEBUG' => 'false',
 
-            'DB_HOST1' => $request->input('db_host'),
-            'DB_PORT1' => $request->input('db_port'),
-            'DB_DATABASE1' => $request->input('db_database'),
-            'DB_USERNAME1' => $request->input('db_username'),
-            'DB_PASSWORD1' => $request->input('db_password'),
+            'DB_HOST' => $request->input('db_host'),
+            'DB_PORT' => $request->input('db_port'),
+            'DB_DATABASE' => $request->input('db_database'),
+            'DB_USERNAME' => $request->input('db_username'),
+            'DB_PASSWORD' => $request->input('db_password'),
 
             'MAIL_MAILER' => $mail_driver,
             'MAIL_PORT' => $request->input('mail_port'),
@@ -125,6 +125,7 @@ class SetupController extends Controller
             'MAIL_PASSWORD' => $request->input('mail_password'),
 
             'NINJA_ENVIRONMENT' => 'selfhost',
+            'DB_CONNECTION' => 'mysql',
         ];
 
         if (config('ninja.db.multi_db_enabled')) {
@@ -133,11 +134,11 @@ class SetupController extends Controller
 
         if (config('ninja.preconfigured_install')) {
             // Database connection was already configured. Don't let the user override it.
-            unset($env_values['DB_HOST1']);
-            unset($env_values['DB_PORT1']);
-            unset($env_values['DB_DATABASE1']);
-            unset($env_values['DB_USERNAME1']);
-            unset($env_values['DB_PASSWORD1']);
+            unset($env_values['DB_HOST']);
+            unset($env_values['DB_PORT']);
+            unset($env_values['DB_DATABASE']);
+            unset($env_values['DB_USERNAME']);
+            unset($env_values['DB_PASSWORD']);
         }
 
         try {
diff --git a/app/Services/Client/ClientService.php b/app/Services/Client/ClientService.php
index 7b1b27dcfcad..9289a53604f1 100644
--- a/app/Services/Client/ClientService.php
+++ b/app/Services/Client/ClientService.php
@@ -51,6 +51,7 @@ class ClientService
         $credits = $this->client->credits
                       ->where('is_deleted', false)
                       ->where('balance', '>', 0)
+                      ->where('due_date', '<=', now())
                       ->sortBy('created_at');
 
         return Number::roundValue($credits->sum('balance'), $this->client->currency()->precision);
diff --git a/config/ninja.php b/config/ninja.php
index 675ce11ae92d..53dd12331057 100644
--- a/config/ninja.php
+++ b/config/ninja.php
@@ -14,8 +14,8 @@ return [
     'require_https' => env('REQUIRE_HTTPS', true),
     'app_url' => rtrim(env('APP_URL', ''), '/'),
     'app_domain' => env('APP_DOMAIN', 'invoicing.co'),
-    'app_version' => '5.2.7',
-    'app_tag' => '5.2.7',
+    'app_version' => '5.2.8',
+    'app_tag' => '5.2.8',
     'minimum_client_version' => '5.0.16',
     'terms_version' => '1.0.1',
     'api_secret' => env('API_SECRET', ''),
diff --git a/tests/MockUnitData.php b/tests/MockUnitData.php
new file mode 100644
index 000000000000..c0baea083e25
--- /dev/null
+++ b/tests/MockUnitData.php
@@ -0,0 +1,71 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://opensource.org/licenses/AAL
+ */
+
+namespace Tests;
+
+use App\Models\Account;
+use App\Models\Client;
+use App\Models\ClientContact;
+use App\Models\Company;
+use App\Models\User;
+/**
+ * Class MockUnitData.
+ */
+trait MockUnitData
+{
+    public $account;
+
+    public $company;
+
+    public $user;
+
+    public $client;
+
+    public $faker;
+
+    public $primary_contact;
+
+    public function makeTestData()
+    {
+
+        $this->faker = \Faker\Factory::create();
+
+        $this->account = Account::factory()->create();
+
+        $this->user = User::factory()->create([
+            'account_id' => $this->account->id, 
+            'email' => $this->faker->safeEmail
+        ]);
+
+        $this->company = Company::factory()->create([
+            'account_id' => $this->account->id
+        ]);
+
+        $this->client = Client::factory()->create([
+            'user_id' => $this->user->id, 
+            'company_id' => $this->company->id
+        ]);
+            
+        $this->primary_contact = ClientContact::factory()->create([
+            'user_id' => $this->user->id,
+            'client_id' => $this->client->id,
+            'company_id' => $this->company->id,
+            'is_primary' => 1,
+        ]);
+
+        ClientContact::factory()->count(2)->create([
+            'user_id' => $this->user->id,
+            'client_id' => $this->client->id,
+            'company_id' => $this->company->id,
+        ]);
+
+    }
+}
\ No newline at end of file
diff --git a/tests/Unit/CreditBalanceTest.php b/tests/Unit/CreditBalanceTest.php
new file mode 100644
index 000000000000..263409b4a854
--- /dev/null
+++ b/tests/Unit/CreditBalanceTest.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://opensource.org/licenses/AAL
+ */
+namespace Tests\Unit;
+
+use App\Models\Account;
+use App\Models\Client;
+use App\Models\Company;
+use App\Models\Credit;
+use App\Models\User;
+use Tests\MockUnitData;
+use Tests\TestCase;
+
+/**
+ * @test
+ */
+class CreditBalanceTest extends TestCase
+{
+    use MockUnitData;
+
+    public function setUp() :void
+    {
+        parent::setUp();
+    
+        $this->makeTestData();
+    }
+
+    public function testCreditBalance()
+    {
+
+        $credit = Credit::factory()->create([
+            'user_id' => $this->user->id,
+            'company_id' => $this->company->id,
+            'client_id' => $this->client->id,
+            'balance' => 10,
+            'number' => 'testing-number-01',
+            'status_id' => Credit::STATUS_SENT,
+        ]);
+
+        $this->assertEquals($this->client->service()->getCreditBalance(), 10);
+    }
+
+
+    public function testExpiredCreditBalance()
+    {
+
+        $credit = Credit::factory()->create([
+            'user_id' => $this->user->id,
+            'company_id' => $this->company->id,
+            'client_id' => $this->client->id,
+            'balance' => 10,
+            'due_date' => now()->addDays(5),
+            'number' => 'testing-number-02',
+            'status_id' => Credit::STATUS_SENT,
+        ]);
+
+        $this->assertEquals($this->client->service()->getCreditBalance(), 0);
+        
+    }
+}