diff --git a/lib/postnord.rb b/lib/postnord.rb
index 85eea2f..cee5e73 100644
--- a/lib/postnord.rb
+++ b/lib/postnord.rb
@@ -4,6 +4,7 @@
 require 'json'
 require 'openssl'
 
+require 'postnord/config'
 require 'postnord/client'
 require 'postnord/response'
 require 'postnord/base'
diff --git a/lib/postnord/client.rb b/lib/postnord/client.rb
index 25eb305..719ff84 100644
--- a/lib/postnord/client.rb
+++ b/lib/postnord/client.rb
@@ -1,24 +1,20 @@
 module Postnord
   class Client
-    POSTNORD_API_KEY = ''
-    POSTNORD_API_VERSION = 'v1'
-    POSTNORD_API_ENDPOINT = 'https://api2.postnord.com/rest'
-    POSTNORD_LOCALE = 'en'
-    POSTNORD_RETURN_TYPE = 'json'
 
     def initialize(options={})
-      @api_version = options[:api_version] || POSTNORD_API_VERSION
-      @api_key = options[:api_key] || POSTNORD_API_KEY
-      @locale = options[:locale] || POSTNORD_LOCALE || 'en'
-      @returntype = options[:returntype] || POSTNORD_RETURN_TYPE || 'json'
+      @api_version  = options[:api_version]  || Config.api_version
+      @api_key      = options[:api_key]      || Config.api_key
+      @api_endpoint = options[:api_endpoint] || Config.api_endpoint
+      @locale       = options[:locale]       || Config.locale
+      @return_type  = options[:return_type]  || Config.return_type
     end
 
     def do_request(service, endpoint, params={})
       uri = build_uri(service, endpoint)
 
       params.merge!(
-        apikey: POSTNORD_API_KEY,
-        locale: POSTNORD_LOCALE,
+        apikey: @api_key,
+        locale: @locale,
       )
 
       uri.query = URI.encode_www_form(params)
@@ -35,11 +31,11 @@ def do_request(service, endpoint, params={})
 
     def build_uri(service, endpoint)
       URI(
-        POSTNORD_API_ENDPOINT +
+        @api_endpoint +
         '/' + service +
-        '/' + POSTNORD_API_VERSION +
+        '/' + @api_version +
         '/' + endpoint +
-        '.' + POSTNORD_RETURN_TYPE
+        '.' + @return_type
       )
     end
   end