diff --git a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOauthClientCredentialClientCommand.php b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOauthClientCredentialClientCommand.php
index 61a9b0a47..a4ec48416 100644
--- a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOauthClientCredentialClientCommand.php
+++ b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOauthClientCredentialClientCommand.php
@@ -54,8 +54,10 @@ class SaveOauthClientCredentialClientCommand implements SaveEntityCommandInterfa
     #[SpDashboardAssert\ValidClientId]
     #[SpDashboardAssert\UniqueEntityId]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 300)]
     private ?string $entityId = null;
 
+    #[Assert\Length(max: 300)]
     private ?string $secret = null;
 
     private ?bool $isPublicClient = null;
@@ -77,6 +79,7 @@ class SaveOauthClientCredentialClientCommand implements SaveEntityCommandInterfa
     #[SpDashboardAssert\ValidLogo()]
     #[Assert\Url]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $logoUrl;
 
     /**
@@ -90,12 +93,14 @@ class SaveOauthClientCredentialClientCommand implements SaveEntityCommandInterfa
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameNl;
 
     /**
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameEn;
 
     /**
@@ -148,6 +153,7 @@ class SaveOauthClientCredentialClientCommand implements SaveEntityCommandInterfa
     /**
      * @var string
      */
+    #[Assert\Length(max: 300)]
     private $comments;
 
     /**
diff --git a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngEntityCommand.php b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngEntityCommand.php
index fab99a436..180eea818 100644
--- a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngEntityCommand.php
+++ b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngEntityCommand.php
@@ -60,11 +60,13 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
     #[SpDashboardAssert\ValidClientId()]
     #[SpDashboardAssert\UniqueEntityId()]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 300)]
     private ?string $entityId = null;
 
     /**
      * @var string
      */
+    #[Assert\Length(max: 255)]
     private $secret;
 
     /**
@@ -105,6 +107,7 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
     #[SpDashboardAssert\ValidLogo()]
     #[Assert\Url]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $logoUrl;
 
     /**
@@ -118,12 +121,14 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameNl;
 
     /**
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameEn;
 
     /**
@@ -144,6 +149,7 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
      * @var string
      */
     #[Assert\Url]
+    #[Assert\Length(max: 300)]
     private $applicationUrl;
 
     /** @var TypeOfService[] */
@@ -163,6 +169,7 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
      * @var string
      */
     #[Assert\Url]
+    #[Assert\Length(max: 300)]
     private $eulaUrl;
 
     /**
@@ -192,6 +199,7 @@ class SaveOidcngEntityCommand implements SaveEntityCommandInterface
     /**
      * @var string
      */
+    #[Assert\Length(max: 300)]
     private $comments;
 
     /**
diff --git a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngResourceServerEntityCommand.php b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngResourceServerEntityCommand.php
index 9b3414b5c..01489cdac 100644
--- a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngResourceServerEntityCommand.php
+++ b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveOidcngResourceServerEntityCommand.php
@@ -56,23 +56,27 @@ class SaveOidcngResourceServerEntityCommand implements SaveEntityCommandInterfac
     #[SpDashboardAssert\ValidClientId]
     #[SpDashboardAssert\UniqueEntityId]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 300)]
     private ?string $entityId = null;
 
     /**
      * @var string
      */
+    #[Assert\Length(max: 255)]
     private $secret;
 
     /**
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameNl;
 
     /**
      * @var string
      */
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private $nameEn;
 
     /**
@@ -113,6 +117,7 @@ class SaveOidcngResourceServerEntityCommand implements SaveEntityCommandInterfac
     /**
      * @var string
      */
+    #[Assert\Length(max: 300)]
     private $comments;
 
     /**
diff --git a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveSamlEntityCommand.php b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveSamlEntityCommand.php
index 9a57c7389..9c80b9792 100644
--- a/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveSamlEntityCommand.php
+++ b/src/Surfnet/ServiceProviderDashboard/Application/Command/Entity/SaveSamlEntityCommand.php
@@ -80,6 +80,8 @@ class SaveSamlEntityCommand implements SaveEntityCommandInterface
     #[SpDashboardAssert\ValidEntityId()]
     #[SpDashboardAssert\UniqueEntityId()]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
+
     private string $entityId;
 
     #[SpDashboardAssert\ValidSSLCertificate()]
@@ -88,12 +90,15 @@ class SaveSamlEntityCommand implements SaveEntityCommandInterface
     #[SpDashboardAssert\ValidLogo()]
     #[Assert\Url]
     #[Assert\NotBlank]
+    #[Assert\Length(max: 300)]
     private ?string $logoUrl = null;
 
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private ?string $nameNl = null;
 
     #[Assert\NotBlank]
+    #[Assert\Length(max: 255)]
     private ?string $nameEn = null;
 
     #[Assert\NotBlank]
@@ -105,6 +110,7 @@ class SaveSamlEntityCommand implements SaveEntityCommandInterface
     private ?string $descriptionEn = null;
 
     #[Assert\Url]
+    #[Assert\Length(max: 300)]
     private ?string $applicationUrl = null;
 
     /** @var TypeOfService[] */
@@ -121,6 +127,7 @@ class SaveSamlEntityCommand implements SaveEntityCommandInterface
     private array $typeOfService = [];
 
     #[Assert\Url]
+    #[Assert\Length(max: 300)]
     private ?string $eulaUrl = null;
 
     
@@ -143,6 +150,7 @@ class SaveSamlEntityCommand implements SaveEntityCommandInterface
     )]
     private array $attributes = [];
 
+    #[Assert\Length(max: 300)]
     private ?string $comments = null;
 
     #[Assert\Choice(callback: [Constants::class, 'getValidNameIdFormats'], strict: true)]
diff --git a/src/Surfnet/ServiceProviderDashboard/Domain/ValueObject/Contact.php b/src/Surfnet/ServiceProviderDashboard/Domain/ValueObject/Contact.php
index f0090f079..e1109e4a6 100644
--- a/src/Surfnet/ServiceProviderDashboard/Domain/ValueObject/Contact.php
+++ b/src/Surfnet/ServiceProviderDashboard/Domain/ValueObject/Contact.php
@@ -30,15 +30,18 @@ class Contact implements Stringable
      * @var string
      */
     #[Assert\NotBlank(groups: ['Default', 'production'])]
+    #[Assert\Length(max: 150)]
     private $firstName;
 
     /**
      * @var string
      */
     #[Assert\NotBlank(groups: ['Default', 'production'])]
+    #[Assert\Length(max: 150)]
     private $lastName;
 
     #[Assert\NotBlank(groups: ['Default', 'production'])]
+    #[Assert\Length(max: 200)]
     private string|null|array $email = null;
 
     /**