diff --git a/Admin/Uninstaller.php b/Admin/Uninstaller.php
index 85d7120..caef30c 100644
--- a/Admin/Uninstaller.php
+++ b/Admin/Uninstaller.php
@@ -29,23 +29,4 @@ use phpOMS\Module\UninstallerAbstract;
  */
 class Uninstaller extends UninstallerAbstract
 {
-
-    /**
-     * {@inheritdoc}
-     */
-    public static function uninstall(DatabasePool $dbPool, InfoManager $info) : void
-    {
-        parent::uninstall($dbPool, $info);
-
-        $query = new Builder($dbPool->get());
-
-        $query->prefix($dbPool->get()->getPrefix())->drop(
-            'accounting_posting_ele',
-            'accounting_posting',
-            'accounting_batch',
-            'accounting_account'
-        );
-
-        $dbPool->get()->con->prepare($query->toSql())->execute();
-    }
 }
diff --git a/Models/AccountAbstract.php b/Models/AccountAbstract.php
index 893c450..3b810e3 100644
--- a/Models/AccountAbstract.php
+++ b/Models/AccountAbstract.php
@@ -36,22 +36,18 @@ abstract class AccountAbstract
     /**
      * Type.
      *
-     * @var \Modules\Accounting\Models\AccountType
+     * @var AccountType
      * @since 1.0.0
      */
-    protected $type = null;
-
-    protected $positiveParent = null;
-
-    protected $negativeParent = null;
+    protected $type = AccountType::IMPERSONAL;
 
     /**
      * Entry list.
      *
-     * @var \Modules\Accounting\Models\EntryInterface[]
+     * @var EntryInterface[]
      * @since 1.0.0
      */
-    protected $entryList = [];
+    protected $entries = [];
 
     /**
      * Constructor.
@@ -65,6 +61,13 @@ abstract class AccountAbstract
         $this->id = $id;
     }
 
+    /**
+     * Get account id.
+     *
+     * @return int
+     *
+     * @since  1.0.0
+     */
     public function getId() : int
     {
         return $this->id;
@@ -75,12 +78,13 @@ abstract class AccountAbstract
      *
      * @param int $id Entry ID
      *
-     * @return void
+     * @return null|EntryInterface
      *
      * @since  1.0.0
      */
-    public function getEntryById($id)
+    public function getEntryById(int $id) : ?EntryInterface
     {
+        return $this->entries[$id] ?? null;
     }
 
     /**
@@ -90,31 +94,12 @@ abstract class AccountAbstract
      * @param \DateTime $end      Interval end
      * @param int       $dateType
      *
-     * @internal \Modules\Accounting\Models\TimeRangeType $dateTime Time range type
+     * @return array
      *
      * @since    1.0.0
      */
-    public function getEntriesByDate($start, $end, $dateType = TimeRangeType::RECEIPT_DATE)
+    public function getEntriesByDate(\DateTime $start, \DateTime $end, int $dateType = TimeRangeType::RECEIPT_DATE) : array
     {
-    }
-
-    public function getPositiveParent()
-    {
-        return $this->positiveParent;
-    }
-
-    public function setPositiveParent($parent)
-    {
-        $this->positiveParent = $parent;
-    }
-
-    public function getNegativeParent()
-    {
-        return $this->negativeParent;
-    }
-
-    public function setNegativeParent($parent)
-    {
-        $this->negativeParent = $parent;
+        return [];
     }
 }
diff --git a/Models/Balance.php b/Models/Balance.php
index 668d5ee..b8261f3 100644
--- a/Models/Balance.php
+++ b/Models/Balance.php
@@ -14,7 +14,6 @@ declare(strict_types=1);
 
 namespace Modules\Accounting\Models;
 
-
 /**
  * Balance class.
  *
@@ -43,21 +42,82 @@ class Balance
     private $balance = [];
 
     /**
-     * Constructor.
+     * Balance name.
      *
-     * @since  1.0.0
+     * @var string
+     * @since 1.0.0
      */
-    public function __construct()
-    {
-    }
+    private $name = '';
 
     /**
+     * Balance description.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $description = '';
+
+    /**
+     * Get balance id
+     *
      * @return int
      *
      * @since  1.0.0
      */
-    public function getId()
+    public function getId() : int
     {
         return $this->id;
     }
+
+    /**
+     * Set name
+     *
+     * @param string $name Balance name
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setName(string $name) : void
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Get name
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getName() : string
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set description
+     *
+     * @param string $description Balance description
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setDescription(string $description) : void
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get description
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getDescription() : string
+    {
+        return $this->description;
+    }
 }
diff --git a/Models/BatchPosting.php b/Models/BatchPosting.php
index 13df748..0622ccb 100644
--- a/Models/BatchPosting.php
+++ b/Models/BatchPosting.php
@@ -60,7 +60,7 @@ class BatchPosting implements \Countable
     /**
      * Postings.
      *
-     * @var \Modules\Accounting\Models\PostingAbstract[]
+     * @var PostingAbstract[]
      * @since 1.0.0
      */
     private $postings = [];
@@ -82,7 +82,7 @@ class BatchPosting implements \Countable
      *
      * @since  1.0.0
      */
-    public function getId()
+    public function getId() : int
     {
         return $this->id;
     }
@@ -108,7 +108,7 @@ class BatchPosting implements \Countable
      *
      * @since  1.0.0
      */
-    public function setDescription(string $desc)
+    public function setDescription(string $desc) : void
     {
         $this->description = $desc;
     }
@@ -146,7 +146,7 @@ class BatchPosting implements \Countable
      *
      * @since  1.0.0
      */
-    public function setCreator($creator)
+    public function setCreator($creator) : void
     {
         $this->creator = $creator;
     }
@@ -156,13 +156,13 @@ class BatchPosting implements \Countable
      *
      * @param int $id Posting ID
      *
-     * @return \Modules\Accounting\Models\PostingAbstract
+     * @return null|PostingAbstract
      *
      * @since  1.0.0
      */
-    public function getPosting($id)
+    public function getPosting(int $id) : ?PostingAbstract
     {
-        return $this->postings[$id];
+        return $this->postings[$id] ?? null;
     }
 
     /**
@@ -170,25 +170,31 @@ class BatchPosting implements \Countable
      *
      * @param int $id Posting ID
      *
-     * @return void
+     * @return bool
      *
      * @since  1.0.0
      */
-    public function removePosting($id)
+    public function removePosting($id) : bool
     {
+        if (!isset($this->postings[$id])) {
+            return false;
+        }
+            
         unset($this->postings[$id]);
+
+        return true;
     }
 
     /**
      * Add posting.
      *
-     * @param \Modules\Accounting\Models\PostingAbstract $posting Posting
+     * @param PostingAbstract $posting Posting
      *
      * @return void
      *
      * @since  1.0.0
      */
-    public function addPosting($posting)
+    public function addPosting(PostingAbstract $posting) : void
     {
         $this->postings[] = $posting;
     }
@@ -196,7 +202,7 @@ class BatchPosting implements \Countable
     /**
      * {@inheritdoc}
      */
-    public function count()
+    public function count() : int
     {
         return count($this->postings);
     }
diff --git a/Models/CostCenter.php b/Models/CostCenter.php
index e69de29..29e30ed 100644
--- a/Models/CostCenter.php
+++ b/Models/CostCenter.php
@@ -0,0 +1,148 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.2
+ *
+ * @package    Modules\Accounting\Models
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://website.orange-management.de
+ */
+declare(strict_types=1);
+
+namespace Modules\Accounting\Models;
+
+/**
+ * BatchPosting class.
+ *
+ * @package    Modules\Accounting\Models
+ * @license    OMS License 1.0
+ * @link       http://website.orange-management.de
+ * @since      1.0.0
+ */
+class CostCenter
+{
+    /**
+     * ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private $id = 0;
+
+    /**
+     * Code.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $code = '';
+
+    /**
+     * Name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $name = '';
+
+    /**
+     * Description.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $description = '';
+
+    /**
+     * Get balance id
+     *
+     * @return int
+     *
+     * @since  1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set code
+     *
+     * @param string $code Balance code
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setCode(string $code) : void
+    {
+        $this->code = $code;
+    }
+
+    /**
+     * Get code
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getCode() : string
+    {
+        return $this->code;
+    }
+
+    /**
+     * Set name
+     *
+     * @param string $name Balance name
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setName(string $name) : void
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Get name
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getName() : string
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set description
+     *
+     * @param string $description Balance description
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setDescription(string $description) : void
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get description
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getDescription() : string
+    {
+        return $this->description;
+    }
+}
\ No newline at end of file
diff --git a/Models/CostObject.php b/Models/CostObject.php
index e69de29..a5207e8 100644
--- a/Models/CostObject.php
+++ b/Models/CostObject.php
@@ -0,0 +1,148 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.2
+ *
+ * @package    Modules\Accounting\Models
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://website.orange-management.de
+ */
+declare(strict_types=1);
+
+namespace Modules\Accounting\Models;
+
+/**
+ * BatchPosting class.
+ *
+ * @package    Modules\Accounting\Models
+ * @license    OMS License 1.0
+ * @link       http://website.orange-management.de
+ * @since      1.0.0
+ */
+class CostObject
+{
+    /**
+     * ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private $id = 0;
+
+    /**
+     * Code.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $code = '';
+
+    /**
+     * Name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $name = '';
+
+    /**
+     * Description.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private $description = '';
+
+    /**
+     * Get balance id
+     *
+     * @return int
+     *
+     * @since  1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set code
+     *
+     * @param string $code Balance code
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setCode(string $code) : void
+    {
+        $this->code = $code;
+    }
+
+    /**
+     * Get code
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getCode() : string
+    {
+        return $this->code;
+    }
+
+    /**
+     * Set name
+     *
+     * @param string $name Balance name
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setName(string $name) : void
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Get name
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getName() : string
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set description
+     *
+     * @param string $description Balance description
+     *
+     * @return void
+     *
+     * @since  1.0.0
+     */
+    public function setDescription(string $description) : void
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get description
+     *
+     * @return string
+     *
+     * @since  1.0.0
+     */
+    public function getDescription() : string
+    {
+        return $this->description;
+    }
+}
\ No newline at end of file
diff --git a/Models/CreditPosting.php b/Models/CreditPosting.php
deleted file mode 100644
index e69de29..0000000
diff --git a/Models/Creditor.php b/Models/Creditor.php
index 00bdf1a..a379023 100644
--- a/Models/Creditor.php
+++ b/Models/Creditor.php
@@ -14,6 +14,8 @@ declare(strict_types=1);
 
 namespace Modules\Accounting\Models;
 
+use Modules\Admin\Models\Account;
+
 /**
  * Creditor class.
  *
@@ -26,11 +28,42 @@ class Creditor
 {
 
     /**
-     * Constructor.
+     * Creditor ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected $id = 0;
+
+    /**
+     * Account.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected $account = null;
+
+    /**
+     * Get id.
+     *
+     * @return int
      *
      * @since  1.0.0
      */
-    public function __construct()
+    public function getId() : int
     {
+        return $this->id;
+    }
+
+    /**
+     * Get account.
+     *
+     * @return null|int|Account
+     *
+     * @since  1.0.0
+     */
+    public function getAccount()
+    {
+        return $this->account;
     }
 }
diff --git a/Models/CreditorAccount.php b/Models/CreditorAccount.php
deleted file mode 100644
index b6fba1d..0000000
--- a/Models/CreditorAccount.php
+++ /dev/null
@@ -1,45 +0,0 @@
-<?php
-/**
- * Orange Management
- *
- * PHP Version 7.2
- *
- * @package    Modules\Accounting\Models
- * @copyright  Dennis Eichhorn
- * @license    OMS License 1.0
- * @version    1.0.0
- * @link       http://website.orange-management.de
- */
-declare(strict_types=1);
-
-namespace Modules\Accounting\Models;
-
-
-/**
- * Creditor account class.
- *
- * @package    Modules\Accounting\Models
- * @license    OMS License 1.0
- * @link       http://website.orange-management.de
- * @since      1.0.0
- */
-abstract class CreditorAccount extends PersonalAccountAbstract
-{
-
-    /**
-     * Constructor.
-     *
-     * @since  1.0.0
-     */
-    public function __construct()
-    {
-    }
-
-    public function getPDO()
-    {
-    }
-
-    public function getDefault()
-    {
-    }
-}
diff --git a/Models/DebitPosting.php b/Models/DebitPosting.php
deleted file mode 100644
index e69de29..0000000
diff --git a/Models/Debitor.php b/Models/Debitor.php
index 7f27583..d2e41bc 100644
--- a/Models/Debitor.php
+++ b/Models/Debitor.php
@@ -14,6 +14,8 @@ declare(strict_types=1);
 
 namespace Modules\Accounting\Models;
 
+use Modules\Admin\Models\Account;
+
 /**
  * Debitor class.
  *
@@ -26,11 +28,42 @@ class Debitor
 {
 
     /**
-     * Constructor.
+     * Debitor ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected $id = 0;
+
+    /**
+     * Account.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected $account = null;
+
+    /**
+     * Get id.
+     *
+     * @return int
      *
      * @since  1.0.0
      */
-    public function __construct()
+    public function getId() : int
     {
+        return $this->id;
+    }
+
+    /**
+     * Get account.
+     *
+     * @return null|int|Account
+     *
+     * @since  1.0.0
+     */
+    public function getAccount()
+    {
+        return $this->account;
     }
 }
diff --git a/Models/DebitorAccount.php b/Models/DebitorAccount.php
deleted file mode 100644
index 4114ffc..0000000
--- a/Models/DebitorAccount.php
+++ /dev/null
@@ -1,49 +0,0 @@
-<?php
-/**
- * Orange Management
- *
- * PHP Version 7.2
- *
- * @package    Modules\Accounting\Models
- * @copyright  Dennis Eichhorn
- * @license    OMS License 1.0
- * @version    1.0.0
- * @link       http://website.orange-management.de
- */
-declare(strict_types=1);
-
-namespace Modules\Accounting\Models;
-
-
-/**
- * DebitorAccount class.
- *
- * @package    Modules\Accounting\Models
- * @license    OMS License 1.0
- * @link       http://website.orange-management.de
- * @since      1.0.0
- */
-abstract class DebitorAccount extends PersonalAccountAbstract
-{
-
-    /**
-     * Constructor.
-     *
-     * @since  1.0.0
-     */
-    public function __construct()
-    {
-    }
-
-    public function getDSO()
-    {
-    }
-
-    public function getDefault()
-    {
-    }
-
-    public function getNetReceivable()
-    {
-    }
-}
diff --git a/Models/ImpersonalAccount.php b/Models/ImpersonalAccount.php
deleted file mode 100644
index d3db591..0000000
--- a/Models/ImpersonalAccount.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-/**
- * Orange Management
- *
- * PHP Version 7.2
- *
- * @package    Modules\Accounting\Models
- * @copyright  Dennis Eichhorn
- * @license    OMS License 1.0
- * @version    1.0.0
- * @link       http://website.orange-management.de
- */
-declare(strict_types=1);
-
-namespace Modules\Accounting\Models;
-
-
-/**
- * ImpersonalAccount class.
- *
- * @package    Modules\Accounting\Models
- * @license    OMS License 1.0
- * @link       http://website.orange-management.de
- * @since      1.0.0
- */
-class ImpersonalAccount
-{
-
-    /**
-     * Constructor.
-     *
-     * @since  1.0.0
-     */
-    public function __construct()
-    {
-    }
-}
diff --git a/Models/InvoicePostingSimple.php b/Models/InvoicePostingSimple.php
deleted file mode 100644
index 293b860..0000000
--- a/Models/InvoicePostingSimple.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-/**
- * Orange Management
- *
- * PHP Version 7.2
- *
- * @package    Modules\Accounting\Models
- * @copyright  Dennis Eichhorn
- * @license    OMS License 1.0
- * @version    1.0.0
- * @link       http://website.orange-management.de
- */
-declare(strict_types=1);
-
-namespace Modules\Accounting\Models;
-
-/**
- * Invoice posting simple class.
- *
- * @package    Modules\Accounting\Models
- * @license    OMS License 1.0
- * @link       http://website.orange-management.de
- * @since      1.0.0
- */
-abstract class InvoicePostingSimple extends PostingAbstract
-{
-
-    /**
-     * Constructor.
-     *
-     * @since  1.0.0
-     */
-    public function __construct()
-    {
-    }
-}
diff --git a/Models/PersonalAccountAbstract.php b/Models/PersonalAccountAbstract.php
deleted file mode 100644
index dc4134d..0000000
--- a/Models/PersonalAccountAbstract.php
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-/**
- * Orange Management
- *
- * PHP Version 7.2
- *
- * @package    Modules\Accounting\Models
- * @copyright  Dennis Eichhorn
- * @license    OMS License 1.0
- * @version    1.0.0
- * @link       http://website.orange-management.de
- */
-declare(strict_types=1);
-
-namespace Modules\Accounting\Models;
-
-/**
- * ImpersonalAccount class.
- *
- * @package    Modules\Accounting\Models
- * @license    OMS License 1.0
- * @link       http://website.orange-management.de
- * @since      1.0.0
- */
-abstract class PersonalAccountAbstract extends AccountAbstract
-{
-    public function __construct(int $id)
-    {
-        parent::__construct($id);
-    }
-
-    public function getBalance()
-    {
-    }
-
-    public function getAccountsReceivable()
-    {
-    }
-
-    public function getAccountsPayable()
-    {
-    }
-
-    public function getAccountsHistory($start, $end)
-    {
-    }
-}