diff --git a/src/Entity/Parts/PartLot.php b/src/Entity/Parts/PartLot.php
index 3d42968f..884bdbcf 100644
--- a/src/Entity/Parts/PartLot.php
+++ b/src/Entity/Parts/PartLot.php
@@ -35,6 +35,7 @@ namespace App\Entity\Parts;
 use App\Entity\Base\DBElement;
 use App\Entity\Base\TimestampTrait;
 use App\Validator\Constraints\Selectable;
+use App\Validator\Constraints\ValidPartLot;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Validator\Constraints as Assert;
 
@@ -45,6 +46,7 @@ use Symfony\Component\Validator\Constraints as Assert;
  * @ORM\Entity()
  * @ORM\Table(name="part_lots")
  * @ORM\HasLifecycleCallbacks()
+ * @ValidPartLot()
  */
 class PartLot extends DBElement
 {
diff --git a/src/Validator/Constraints/ValidPartLot.php b/src/Validator/Constraints/ValidPartLot.php
new file mode 100644
index 00000000..964a118c
--- /dev/null
+++ b/src/Validator/Constraints/ValidPartLot.php
@@ -0,0 +1,49 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 Jan Böhmer
+ * https://github.com/jbtronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\Validator\Constraints;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * A constraint "dummy" to validate the PartLot.
+ * We need to access services in our Validator, so we can not use a simple callback on PartLot
+ *
+ * @package App\Validator\Constraints
+ * @Annotation
+ */
+class ValidPartLot extends Constraint
+{
+    public function getTargets()
+    {
+        return self::CLASS_CONSTRAINT;
+    }
+}
\ No newline at end of file
diff --git a/src/Validator/Constraints/ValidPartLotValidator.php b/src/Validator/Constraints/ValidPartLotValidator.php
new file mode 100644
index 00000000..8e4489d6
--- /dev/null
+++ b/src/Validator/Constraints/ValidPartLotValidator.php
@@ -0,0 +1,107 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 Jan Böhmer
+ * https://github.com/jbtronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\Validator\Constraints;
+
+
+use App\Entity\Parts\PartLot;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Component\DependencyInjection\Compiler\ValidateEnvPlaceholdersPass;
+use Symfony\Component\Form\Exception\UnexpectedTypeException;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+class ValidPartLotValidator extends ConstraintValidator
+{
+    protected $em;
+
+    public function __construct(EntityManagerInterface $em)
+    {
+        $this->em = $em;
+    }
+
+    /**
+     * Checks if the passed value is valid.
+     *
+     * @param mixed $value The value that should be validated
+     * @param Constraint $constraint The constraint for the validation
+     */
+    public function validate($value, Constraint $constraint)
+    {
+        if (!$constraint instanceof ValidPartLot) {
+            throw new UnexpectedTypeException($constraint, ValidPartLot::class);
+        }
+
+        if (!$value instanceof PartLot) {
+            throw new UnexpectedTypeException($value, PartLot::class);
+        }
+
+        //We can only validate the values if we know the storelocation
+        if ($value->getStorageLocation()) {
+            $parts = $value->getStorageLocation()->getParts();
+
+            //Check for isFull() attribute
+            if ($value->getStorageLocation()->isFull()) {
+                //Compare with saved amount value
+                $db_lot = $this->em->getUnitOfWork()->getOriginalEntityData($value);
+
+                //Amount increasment is not allowed
+                if ($db_lot && $value->getAmount() > $db_lot['amount']) {
+                    $this->context->buildViolation('validator.part_lot.location_full.no_increasment')
+                        ->setParameter('{{ old_amount }}', $db_lot['amount'])
+                        ->atPath('amount')->addViolation();
+                }
+
+                if (!$parts->contains($value->getPart())) {
+                    $this->context->buildViolation('validator.part_lot.location_full')
+                        ->atPath('storage_location')->addViolation();
+                }
+            }
+
+
+            //Check for onlyExisting
+            if ($value->getStorageLocation()->isLimitToExistingParts()) {
+                if (!$parts->contains($value->getPart())) {
+                    $this->context->buildViolation('validator.part_lot.only_existing')
+                        ->atPath('storage_location')->addViolation();
+                }
+            }
+
+            //Check for only single part
+            if ($value->getStorageLocation()->isLimitToExistingParts()) {
+                if (($parts->count() > 0) && !$parts->contains($value->getPart())) {
+                    $this->context->buildViolation('validator.part_lot.single_part')
+                        ->atPath('storage_location')->addViolation();
+                }
+            }
+        }
+    }
+}
\ No newline at end of file