diff --git a/src/Entity/CustomerOptions/CustomerOption.php b/src/Entity/CustomerOptions/CustomerOption.php
index b703a268..19001872 100644
--- a/src/Entity/CustomerOptions/CustomerOption.php
+++ b/src/Entity/CustomerOptions/CustomerOption.php
@@ -54,7 +54,7 @@ public function __construct()
     {
         $this->initializeTranslationsCollection();
 
-        $this->values            = new ArrayCollection();
+        $this->values = new ArrayCollection();
         $this->groupAssociations = new ArrayCollection();
     }
 
@@ -76,12 +76,8 @@ public function setType(?string $type): void
         }
 
         $this->type = $type;
-
-        if (CustomerOptionTypeEnum::isSelect($type)) {
-            $this->configuration = [];
-        } else {
-            $this->configuration = CustomerOptionTypeEnum::getConfigurationArray()[$type];
-        }
+        
+        $this->configuration = CustomerOptionTypeEnum::getConfigurationArray()[$type];
     }
 
     /**
@@ -94,7 +90,7 @@ public function getType(): string
 
     public function getTypeCode(): ?string
     {
-        $type         = $this->getType();
+        $type = $this->getType();
         $translations = CustomerOptionTypeEnum::getTranslateArray();
         if (array_key_exists($type, $translations)) {
             return $translations[$type];
diff --git a/src/Enumerations/CustomerOptionTypeEnum.php b/src/Enumerations/CustomerOptionTypeEnum.php
index 437db041..98fb8c80 100644
--- a/src/Enumerations/CustomerOptionTypeEnum.php
+++ b/src/Enumerations/CustomerOptionTypeEnum.php
@@ -118,6 +118,12 @@ public static function getFormTypeArray(): array
     public static function getConfigurationArray(): array
     {
         return [
+            self::MULTI_SELECT => [
+                'brille24.form.config.min.choice' => ['type' => 'number', 'value' => 0],
+                'brille24.form.config.max.choice' => ['type' => 'number', 'value' => 1000],
+            ],
+            self::SELECT => [
+            ],
             self::TEXT => [
                 'brille24.form.config.min.length' => ['type' => 'number', 'value' => 0],
                 'brille24.form.config.max.length' => ['type' => 'number', 'value' => 255],
diff --git a/src/Form/Product/ShopCustomerOptionType.php b/src/Form/Product/ShopCustomerOptionType.php
index 912c28ae..f9050811 100644
--- a/src/Form/Product/ShopCustomerOptionType.php
+++ b/src/Form/Product/ShopCustomerOptionType.php
@@ -49,11 +49,12 @@ public function __construct(
         CurrencyContextInterface $currencyContext,
         MoneyFormatterInterface $moneyFormatter,
         LocaleContextInterface $localeContext
-    ) {
-        $this->channelContext  = $channelContext;
+    )
+    {
+        $this->channelContext = $channelContext;
         $this->currencyContext = $currencyContext;
-        $this->moneyFormatter  = $moneyFormatter;
-        $this->localeContext   = $localeContext;
+        $this->moneyFormatter = $moneyFormatter;
+        $this->localeContext = $localeContext;
     }
 
     public function buildForm(FormBuilderInterface $builder, array $options): void
@@ -69,11 +70,11 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
 
         foreach ($customerOptions as $customerOption) {
             $customerOptionType = $customerOption->getType();
-            $fieldName          = $customerOption->getCode();
+            $fieldName = $customerOption->getCode();
 
             [$class, $formOptions] = CustomerOptionTypeEnum::getFormTypeArray()[$customerOptionType];
 
-            $fieldConfig           = $this->getFormConfiguration($formOptions, $customerOption, $product);
+            $fieldConfig = $this->getFormConfiguration($formOptions, $customerOption, $product);
             $fieldConfig['mapped'] = $options['mapped'];
 
             $builder->add($fieldName, $class, $fieldConfig);
@@ -110,9 +111,9 @@ public function getBlockPrefix(): string
     /**
      * Gets the settings for the form type based on the type that the form field is for
      *
-     * @param array                   $formOptions
+     * @param array $formOptions
      * @param CustomerOptionInterface $customerOption
-     * @param ProductInterface        $product
+     * @param ProductInterface $product
      *
      * @return array
      */
@@ -120,9 +121,10 @@ private function getFormConfiguration(
         array $formOptions,
         CustomerOptionInterface $customerOption,
         ProductInterface $product
-    ): array {
+    ): array
+    {
         $defaultOptions = [
-            'label'    => $customerOption->getName(),
+            'label' => $customerOption->getName(),
             'required' => $customerOption->isRequired(),
         ];
 
@@ -132,31 +134,30 @@ private function getFormConfiguration(
         $customerOptionType = $customerOption->getType();
         if (CustomerOptionTypeEnum::isSelect($customerOptionType)) {
             $configuration = [
-                'choices'      => $customerOption->getValues()->toArray(),
+                'choices' => $customerOption->getValues()->toArray(),
                 'choice_label' => function (CustomerOptionValueInterface $value) use ($product) {
                     return $this->buildValueString($value, $product);
                 },
                 'choice_value' => 'code',
             ];
-        } else {
-            $constraint = ConstraintCreator::createFromConfiguration(
-                $customerOptionType,
-                $customerOption->getConfiguration()
-            );
+        }
+        $constraint = ConstraintCreator::createFromConfiguration(
+            $customerOptionType,
+            array_merge($customerOption->getConfiguration(), $configuration)
+        );
 
-            if ($constraint !== null) {
-                $constraint->groups = ['sylius'];
-                $configuration      = ['constraints' => [$constraint]];
-            }
+        if ($constraint !== null) {
+            $constraint->groups = ['sylius'];
+            $configuration['constraints'] = [$constraint];
+        }
 
-            if ($customerOption->isRequired()) {
-                /** @var NotBlank $requiredConstraint */
-                $requiredConstraint          = ConstraintCreator::createRequiredConstraint();
-                $requiredConstraint->message = 'brille24.form.customer_options.required';
+        if ($customerOption->isRequired()) {
+            /** @var NotBlank $requiredConstraint */
+            $requiredConstraint = ConstraintCreator::createRequiredConstraint();
+            $requiredConstraint->message = 'brille24.form.customer_options.required';
 
-                $requiredConstraint->groups     = ['sylius'];
-                $configuration['constraints'][] = $requiredConstraint;
-            }
+            $requiredConstraint->groups = ['sylius'];
+            $configuration['constraints'][] = $requiredConstraint;
         }
 
         if ($customerOptionType === CustomerOptionTypeEnum::FILE) {
@@ -174,7 +175,7 @@ private function getFormConfiguration(
 
     /**
      * @param CustomerOptionValueInterface $value
-     * @param ProductInterface             $product
+     * @param ProductInterface $product
      *
      * @return string
      *
@@ -199,7 +200,7 @@ private function buildValueString(CustomerOptionValueInterface $value, ProductIn
 
         /** @var ChannelInterface $channel */
         $channel = $this->channelContext->getChannel();
-        $price   = $price ?? $value->getPriceForChannel($channel);
+        $price = $price ?? $value->getPriceForChannel($channel);
 
         // No price was found for the current channel, probably because the values weren't updated after adding a new channel
         if ($price === null) {
@@ -217,7 +218,7 @@ private function buildValueString(CustomerOptionValueInterface $value, ProductIn
             $this->localeContext->getLocaleCode(),
             $this->moneyFormatter
         );
-        $name        = $value->getName();
+        $name = $value->getName();
 
         return "{$name} ($valueString)";
     }
diff --git a/src/Resources/translations/messages.en.yml b/src/Resources/translations/messages.en.yml
index d7271f33..fc1466fe 100644
--- a/src/Resources/translations/messages.en.yml
+++ b/src/Resources/translations/messages.en.yml
@@ -48,10 +48,12 @@ brille24:
         config:
             min:
                 length: Minimum length
+                choice: Minimum number of selected items
                 file_size: Minimum size
                 date: Minimum date
                 number: Minimum number
             max:
+                choice: Maximum number of selected items
                 length: Maximum length
                 file_size: Maximum size
                 date: Maximum date
diff --git a/src/Resources/views/CustomerOption/_form.html.twig b/src/Resources/views/CustomerOption/_form.html.twig
index 476f3efc..c8d3ce2d 100644
--- a/src/Resources/views/CustomerOption/_form.html.twig
+++ b/src/Resources/views/CustomerOption/_form.html.twig
@@ -16,7 +16,6 @@
     {% set customerOptionType = form.type.vars.value %}
     {% if customerOptionType == 'select' or customerOptionType == 'multi_select' %}
         {% include 'Brille24SyliusCustomerOptionsPlugin:CustomerOption:_values.html.twig' with {'form': form.values} only %}
-    {% else %}
-        {% include 'Brille24SyliusCustomerOptionsPlugin:CustomerOption:_configuration.html.twig' with {'form': form.configuration} only %}
     {% endif %}
+    {% include 'Brille24SyliusCustomerOptionsPlugin:CustomerOption:_configuration.html.twig' with {'form': form.configuration} only %}
 </div>
diff --git a/src/Services/ConstraintCreator.php b/src/Services/ConstraintCreator.php
index 0f828efe..70acfbc5 100644
--- a/src/Services/ConstraintCreator.php
+++ b/src/Services/ConstraintCreator.php
@@ -11,13 +11,14 @@
 use Symfony\Component\Validator\Constraints\Length;
 use Symfony\Component\Validator\Constraints\NotBlank;
 use Symfony\Component\Validator\Constraints\Range;
+use Symfony\Component\Validator\Constraints\Choice;
 
 class ConstraintCreator
 {
     /**
      * Gets the value from the Customer Option value configuration
      *
-     * @param array  $configuration
+     * @param array $configuration
      * @param string $key
      *
      * @return mixed
@@ -35,7 +36,7 @@ public static function getValueFromConfiguration(array $configuration, string $k
      * Creates a constraint form the configuration based on the type of Custom Option
      *
      * @param string $type
-     * @param array  $configuration
+     * @param array $configuration
      *
      * @return Constraint|null
      */
@@ -53,6 +54,14 @@ public static function createFromConfiguration(string $type, array $configuratio
                 ];
 
                 return new Length($lengthRange);
+            case CustomerOptionTypeEnum::MULTI_SELECT:
+                $choiceNumberRange = [
+                    'min' => $getFromConfiguration('brille24.form.config.min.choice'),
+                    'max' => $getFromConfiguration('brille24.form.config.max.choice'),
+                    'choices' =>  $configuration['choices'],
+                    'multiple' => true,
+                ];
+                return new Choice($choiceNumberRange);
             case CustomerOptionTypeEnum::FILE:
                 $allowedFileTypes = explode(',', (string) $getFromConfiguration('brille24.form.config.allowed_types'));
 
@@ -83,7 +92,7 @@ public static function createFromConfiguration(string $type, array $configuratio
     public static function createConditionalConstraint(array $conditions, array $constraints): Constraint
     {
         return new ConditionalConstraint([
-            'conditions'  => $conditions,
+            'conditions' => $conditions,
             'constraints' => $constraints,
         ]);
     }