diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8fda750..a56b4fd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,9 @@
 # Changelog
+### [1.8.3](https://github.com/ratepay/php-library/compare/1.8.2...1.8.3) (2023-01-16)
+
+### Update
+* Change Ratepay address
+
 ### [1.8.2](https://github.com/ratepay/php-library/compare/1.8.1...1.8.2) (2022-09-05)
 
 
diff --git a/README.md b/README.md
index 0d50c0b..4f66255 100755
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ RatePAY Integration Toolkit for PHP
 | Repository | Common RatePAY PHP Library
 |------------|----------
 | Author     | Eduardo Iriarte-Mendez
-| Version    | `1.8.2` [Changelog](./CHANGELOG.md)
+| Version    | `1.8.3` [Changelog](./CHANGELOG.md)
 | Link       | http://www.ratepay.com
 | Mail       | integration@ratepay.com
 
diff --git a/composer.json b/composer.json
index 11417b5..e71dfdd 100755
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "ratepay/php-library",
   "description": "Ratepay Payment-API PHP Library",
-  "version": "1.8.2",
+  "version": "1.8.3",
   "license": "MIT",
   "type": "library",
   "homepage": "https://ratepay.gitbook.io/docs/",
@@ -28,7 +28,7 @@
   },
   "require-dev": {
     "friendsofphp/php-cs-fixer": "^2.17@dev",
-    "donatj/mock-webserver": "dev-master",
+    "donatj/mock-webserver": "~2.5.0",
     "phpunit/phpunit": "^6.5||^7.5||^8.5||^9.0"
   },
   "minimum-stability": "dev",
diff --git a/src/Model/Request/SubModel/Constants.php b/src/Model/Request/SubModel/Constants.php
index 8d89757..850975f 100644
--- a/src/Model/Request/SubModel/Constants.php
+++ b/src/Model/Request/SubModel/Constants.php
@@ -19,7 +19,7 @@ class Constants
     /**
      * Library version.
      */
-    const LIBRARY_VERSION = '1.8.2';
+    const LIBRARY_VERSION = '1.8.3';
 
     /**
      * Supported RatePAY API version.
diff --git a/src/Service/Math.php b/src/Service/Math.php
index 3af02c0..1930b57 100644
--- a/src/Service/Math.php
+++ b/src/Service/Math.php
@@ -28,10 +28,12 @@ public static function isZero($number, $precission = 2)
      */
     public static function netToGross($netPrice, $taxPercentage, $round = false)
     {
-        $withTax = $netPrice + $netPrice * $taxPercentage / 100;
+        $withTax = $netPrice * (1 + $taxPercentage / 100);
 
         if (!$round) {
-            return $withTax;
+            $localInfo = localeconv();
+
+            return floatval(number_format($withTax, 5, $localInfo['decimal_point'], $localInfo['thousands_sep']));
         }
 
         $rounded = round($withTax, 2);
diff --git a/src/locales/de.php b/src/locales/de.php
index 31a5aa9..2deddef 100644
--- a/src/locales/de.php
+++ b/src/locales/de.php
@@ -55,8 +55,8 @@
   'rp_reason_code_translation_699' => 'Die Rate ist zu hoch für die minimal verfügbare Laufzeit. Die Rate wurde verringert.',
   'rp_switch_payment_type_bank_transfer' => 'Ich möchte die Ratenzahlungen selbst vornehmen und nicht per Lastschrift begleichen.',
   'rp_switch_payment_type_direct_debit' => 'Ich möchte die Ratenzahlungen bequem per Lastschrift begleichen.',
-  'rp_address' => 'Ratepay GmbH, Franklinstraße 28-29, 10587 Berlin',
-  'wcd_address' => 'Ratepay GmbH, Franklinstraße 28-29, 10587 Berlin',
+  'rp_address' => 'Ratepay GmbH, Ritterstraße 12-14, 10969 Berlin',
+  'wcd_address' => 'Ratepay GmbH, Ritterstraße 12-14, 10969 Berlin',
   'rp_creditor' => 'Gläubiger-ID',
   'rp_creditor_id' => 'DE39RPY00000568463',
   'wcd_creditor_id' => 'DE39RPY00000568463',
diff --git a/src/locales/en.php b/src/locales/en.php
index 3b50d57..9f8e798 100644
--- a/src/locales/en.php
+++ b/src/locales/en.php
@@ -56,8 +56,8 @@
   'rp_reason_code_translation_699' => 'The instalment is too high for the minimum available runtime. The instalment has been reduced.',
   'rp_switch_payment_type_bank_transfer' => 'I would like to make the instalments myself and not pay by direct debit',
   'rp_switch_payment_type_direct_debit' => 'I would like to pay the instalments conveniently by direct debit',
-  'rp_address' => 'RatePAY GmbH, Franklinstraße 28-29, 10587 Berlin',
-  'wcd_address' => 'RatePAY GmbH, Franklinstraße 28-29, 10587 Berlin',
+  'rp_address' => 'RatePAY GmbH, Ritterstraße 12-14, 10969 Berlin',
+  'wcd_address' => 'RatePAY GmbH, Ritterstraße 12-14, 10969 Berlin',
   'rp_creditor' => 'Creditor ID',
   'rp_creditor_id' => 'DE39RPY00000568463',
   'wcd_creditor_id' => 'DE39RPY00000568463',
diff --git a/tests/Unit/Service/MathTest.php b/tests/Unit/Service/MathTest.php
index d937cf4..a0c4090 100644
--- a/tests/Unit/Service/MathTest.php
+++ b/tests/Unit/Service/MathTest.php
@@ -27,6 +27,8 @@ public function provideNatPricesWithTaxRates()
             [100, 19, 119],
             [100, 0, 100],
             [29.99, 2.5, 30.73975],
+            [1029.99, 2.5, 1055.73975],
+            [12345.99, 8.9, 13444.78311],
         ];
     }
 
@@ -44,6 +46,8 @@ public function provideRoundedNatPricesWithTaxRates()
             [100, 19, 119.00],
             [100, 0, 100.00],
             [29.99, 2.5, 30.74],
+            [1029.99, 2.5, 1055.74],
+            [12345.99, 8.9, 13444.78],
         ];
     }