diff --git a/src/Dto/BisAddress.php b/src/Dto/BisAddress.php
index f2c4f64..6c51306 100644
--- a/src/Dto/BisAddress.php
+++ b/src/Dto/BisAddress.php
@@ -7,77 +7,58 @@ use Spatie\DataTransferObject\DataTransferObject;
 
 /**
  * Business Address
- *
- * - careOf (string, optional): Care of address
- * - street (string, optional): Street address
- * - postCode (string, optional): ZIP code
- * - city (string, optional): City of address
- * - language (string, optional): Two letter language code
- * - type (integer): Type of address, 1 for street address, 2 for postal address
- * - country (string, optional): Two letter country code
  */
 class BisAddress extends DataTransferObject
 {
     use HasSource;
 
     /**
-     * One for current version and >1 for historical company names
-     *
-     * @var int
+     * One for current version and >1 for historical addresses
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate = '';
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
     public ?string $endDate = null;
+
     /**
-     * Care of address (c/o)
-     *
-     * @var string|null
+     * Care of address
      */
-    public ?string $careOf;
+    public ?string $careOf = null;
+
     /**
      * Street address
-     *
-     * @var string|null
      */
-    public ?string $street;
+    public ?string $street = null;
+
     /**
      * ZIP code
-     *
-     * @var string|null
      */
-    public ?string $postCode;
+    public ?string $postCode = null;
+
     /**
      * City of address
-     *
-     * @var string|null
      */
-    public ?string $city;
+    public ?string $city = null;
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
-    public ?string $language;
+    public ?string $language = null;
+
     /**
      * Type of address, 1 for street address, 2 for postal address
-     *
-     * @var int
      */
     public int $type;
+
     /**
-     * Two-letter country code
-     *
-     * @var string|null
+     * Two letter country code
      */
-    public ?string $country;
+    public ?string $country = null;
 }
diff --git a/src/Dto/BisCompanyBusinessIdChange.php b/src/Dto/BisCompanyBusinessIdChange.php
index 59b14c8..80cfbe5 100644
--- a/src/Dto/BisCompanyBusinessIdChange.php
+++ b/src/Dto/BisCompanyBusinessIdChange.php
@@ -7,28 +7,56 @@ use Spatie\DataTransferObject\DataTransferObject;
 
 /**
  * Company Business ID Change
- *
- * - description (string): Description of reason
- * - reason (string): Reason code
- * - changeDate (string, optional): Date of Business ID change
- * - change (integer):
- *      2 = Business ID removal,
- *      3 = Combining of double IDs,
- *      5 = ID changed,
- *      44 = Fusion,
- *      45 = Operator continuing VAT activities,
- *      46 = Relation to predecessor,
- *      47 = Division,
- *      48 = Bankruptcy relationship,
- *      49 = Operations continued by a private trader,
- *      57 = Partial division,
- *      DIF = Division,
- *      FUU = Fusion
- * - oldBusinessId (string): Old Business ID
- * - newBusinessId (string): New Business ID
- * - language (string, optional): Two letter language code
  */
 class BisCompanyBusinessIdChange extends DataTransferObject
 {
     use HasSource;
+
+    /**
+     * Description of reason
+     */
+    public string $description = "";
+
+    /**
+     * Reason code
+     */
+    public string $reason = "";
+
+    /**
+     * Date of Business ID change
+     */
+    public ?string $changeDate = null;
+
+    /**
+     * Business ID Change
+     *
+     * 2 = Business ID removal,
+     * 3 = Combining of double IDs,
+     * 5 = ID changed,
+     * 44 = Fusion,
+     * 45 = Operator continuing VAT activities,
+     * 46 = Relation to predecessor,
+     * 47 = Division,
+     * 48 = Bankruptcy relationship,
+     * 49 = Operations continued by a private trader,
+     * 57 = Partial division,
+     * DIF = Division,
+     * FUU = Fusion
+     */
+    public int $change;
+
+    /**
+     * Old Business ID
+     */
+    public string $oldBusinessId = "";
+
+    /**
+     * New Business ID
+     */
+    public string $newBusinessId = "";
+
+    /**
+     * Two letter language code
+     */
+    public ?string $language = null;
 }
diff --git a/src/Dto/BisCompanyBusinessLine.php b/src/Dto/BisCompanyBusinessLine.php
index 9cb82af..0a06e33 100644
--- a/src/Dto/BisCompanyBusinessLine.php
+++ b/src/Dto/BisCompanyBusinessLine.php
@@ -7,58 +7,38 @@ use Spatie\DataTransferObject\DataTransferObject;
 
 /**
  * Company Business Line
- *
- * - order (integer): Zero for main line of business, positive for others
- * - version (integer):
- *      One for current version and
- *      >1 for historical lines of business
- * - registrationDate (string): Date of registration
- * - endDate (string, optional): Ending date of registration
- * - name (string): Name of line of business
- * - language (string, optional): Two letter language code
  */
 class BisCompanyBusinessLine extends DataTransferObject
 {
     use HasSource;
 
     /**
-     * Order
-     *
-     * Zero for primary company name,
-     * other for translations of the primary company name
-     * and auxiliary company names
-     *
-     * @var int
+     * Zero for main line of business, positive for others
      */
     public int $order;
+
     /**
-     * One for current version and >1 for historical company names
-     *
-     * @var int
+     * One for current version and >1 for historical lines of business
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate = '';
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
     public ?string $endDate = null;
+
     /**
      * Name of line of business
-     *
-     * @var string
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
     public ?string $language = null;
 }
diff --git a/src/Dto/BisCompanyContactDetail.php b/src/Dto/BisCompanyContactDetail.php
index 040ea20..cbb4527 100644
--- a/src/Dto/BisCompanyContactDetail.php
+++ b/src/Dto/BisCompanyContactDetail.php
@@ -14,38 +14,31 @@ class BisCompanyContactDetail extends DataTransferObject
 
     /**
      * One for current version and >1 for historical contact details
-     *
-     * @var int
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate;
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
-    public ?string $endDate;
+    public ?string $endDate = null;
+
     /**
      * Two letter language code
-     *
-     * @var string
      */
-    public string $language;
+    public ?string $language = null;
+
     /**
      * Value of contact detail
-     *
-     * @var string
      */
-    public string $value;
+    public string $value = "";
+
     /**
      * Type of contact detail
-     *
-     * @var string
      */
-    public string $type;
+    public string $type = "";
 }
diff --git a/src/Dto/BisCompanyDetails.php b/src/Dto/BisCompanyDetails.php
index dd9f176..6410bdc 100644
--- a/src/Dto/BisCompanyDetails.php
+++ b/src/Dto/BisCompanyDetails.php
@@ -12,121 +12,104 @@ use Spatie\DataTransferObject\DataTransferObject;
 class BisCompanyDetails extends DataTransferObject
 {
     /**
-     * Business ID
-     *
-     * @var string
+     * Primary company name and translations
+     * @var BisCompanyName[] $names
      */
-    public string $businessId;
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyName::class)]
+    public array $names = [];
+
     /**
-     * Primary company name
-     *
-     * @var string
+     * Auxiliary company name and translations
+     * @var ?BisCompanyName[] $auxiliaryNames
      */
-    public string $name;
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyName::class)]
+    public ?array $auxiliaryNames = [];
+
+    /**
+     * Company's street and postal addresses
+     * @var ?BisAddress[] $addresses
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisAddress::class)]
+    public ?array $addresses = [];
+
+    /**
+     * Company form and translations
+     * @var ?BisCompanyForm[] $companyForms
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyForm::class)]
+    public ?array $companyForms = [];
+
+    /**
+     * Bankruptcy, liquidation or restructuring proceedings
+     * @var ?BisCompanyLiquidation[] $liquidations
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyLiquidation::class)]
+    public ?array $liquidations = [];
+
+    /**
+     * Company's lines of business and translations
+     * @var ?BisCompanyBusinessLine[] $businessLines
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyBusinessLine::class)]
+    public ?array $businessLines = [];
+
+    /**
+     * Company's language(s)
+     * @var ?BisCompanyLanguage[] $languages
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyLanguage::class)]
+    public ?array $languages = [];
+
+    /**
+     * Company's place of registered office and its translations
+     * @var ?BisCompanyRegisteredOffice[] $registeredOffices
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyRegisteredOffice::class)]
+    public ?array $registeredOffices = [];
+
+    /**
+     * Company's contact details and translations
+     * @var ?BisCompanyContactDetail[] $contactDetails
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyContactDetail::class)]
+    public ?array $contactDetails = [];
+
+    /**
+     * Company's registered entries
+     * @var ?BisCompanyRegisteredEntry[] $registeredEntries
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyRegisteredEntry::class)]
+    public ?array $registeredEntries = [];
+
+    /**
+     * Company's Business ID changes
+     * @var ?BisCompanyBusinessIdChange[] $businessIdChanges
+     */
+    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyBusinessIdChange::class)]
+    public ?array $businessIdChanges = [];
+
+    /**
+     * Business ID
+     */
+    public string $businessId = "";
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate;
+    public string $registrationDate = "";
+
     /**
      * Company form
-     *
-     * @var string|null
      */
     public ?string $companyForm = null;
+
     /**
      * A URI for more details, if details aren't already included
-     *
-     * @var string|null
      */
     public ?string $detailsUri = null;
 
     /**
-     * Primary company name and translations
-     *
-     * @var BisCompanyName[] $names
+     * Primary company name
      */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyName::class)]
-    public ?array $names = null;
-
-    /**
-     * Auxiliary company name and translations
-     *
-     * @var BisCompanyName[] $auxiliaryNames
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyName::class)]
-    public ?array $auxiliaryNames = null;
-
-    /**
-     * Company's street and postal addresses
-     *
-     * @var BisAddress[]|null $addresses
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisAddress::class)]
-    public ?array $addresses = null;
-
-    /**
-     * Company form and translations
-     *
-     * @var BisCompanyForm[]|null $companyForms
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyForm::class)]
-    public ?array $companyForms = null;
-
-    /**
-     * Bankruptcy, liquidation or restructuring proceedings
-     *
-     * @var BisCompanyLiquidation[]|null $liquidations
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyLiquidation::class)]
-    public ?array $liquidations = null;
-
-    /**
-     * Company's lines of business and translations
-     *
-     * @var BisCompanyBusinessLine[]|null $businessLines
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyBusinessLine::class)]
-    public ?array $businessLines = null;
-
-    /**
-     * Company's language(s)
-     *
-     * @var BisCompanyLanguage[]|null $languages
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyLanguage::class)]
-    public ?array $languages = null;
-
-    /**
-     * Company's place of registered office and its translations
-     *
-     * @var BisCompanyRegisteredOffice[]|null $registeredOffices
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyRegisteredOffice::class)]
-    public ?array $registeredOffices = null;
-
-    /**
-     * Company's contact details and translations
-     *
-     * @var BisCompanyContactDetail[]|null $contactDetails
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyContactDetail::class)]
-    public ?array $contactDetails = null;
-
-    /**
-     * Company's registered entries
-     *
-     * @var BisCompanyRegisteredEntry[]|null $registeredEntries
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyRegisteredEntry::class)]
-    public ?array $registeredEntries = null;
-
-    /**
-     * Company's Business ID changes
-     *
-     * @var BisCompanyBusinessIdChange[]|null $businessIdChanges
-     */
-    #[CastWith(Casters\ArrayCaster::class, itemType: BisCompanyBusinessIdChange::class)]
-    public ?array $businessIdChanges = null;
+    public string $name = "";
 }
diff --git a/src/Dto/BisCompanyForm.php b/src/Dto/BisCompanyForm.php
index f4e024e..42651a5 100644
--- a/src/Dto/BisCompanyForm.php
+++ b/src/Dto/BisCompanyForm.php
@@ -14,34 +14,29 @@ class BisCompanyForm extends DataTransferObject
 
     /**
      * One for current version and >1 for historical company forms
-     *
-     * @var int
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate;
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
-    public ?string $endDate;
+    public ?string $endDate = null;
+
     /**
      * Name of company form
-     *
-     * @var string
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
-    public ?string $language;
+    public ?string $language = null;
+
     /**
      * Type of company form.
      *
diff --git a/src/Dto/BisCompanyLanguage.php b/src/Dto/BisCompanyLanguage.php
index 5142630..60be812 100644
--- a/src/Dto/BisCompanyLanguage.php
+++ b/src/Dto/BisCompanyLanguage.php
@@ -13,33 +13,32 @@ class BisCompanyLanguage extends DataTransferObject
     use HasSource;
 
     /**
-     * One for current version and >1 for historical company names
-     *
-     * @var int
+     * One for current version and >1 for historical company forms
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate = '';
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
     public ?string $endDate = null;
+
     /**
-     * Company name
-     *
-     * @var string
+     * Bankruptcy, liquidation or restructuring proceedings
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
     public ?string $language = null;
+
+    /**
+     * Type of liquidation
+     */
+    public string $type = "";
 }
diff --git a/src/Dto/BisCompanyLiquidation.php b/src/Dto/BisCompanyLiquidation.php
index 31d86a1..90cc906 100644
--- a/src/Dto/BisCompanyLiquidation.php
+++ b/src/Dto/BisCompanyLiquidation.php
@@ -7,58 +7,38 @@ use Spatie\DataTransferObject\DataTransferObject;
 
 /**
  * Company Liquidation
- *
- * - version (integer): One for current version and >1 for historical company forms
- * - registrationDate (string): Date of registration
- * - endDate (string, optional): Ending date of registration
- * - name (string): Bankruptcy, liquidation or restructuring proceedings
- * - language (string, optional): Two letter language code
- * - type (string): Type of liquidation
  */
 class BisCompanyLiquidation extends DataTransferObject
 {
     use HasSource;
 
     /**
-     * Order
-     *
-     * Zero for primary company name,
-     * other for translations of the primary company name
-     * and auxiliary company names
-     *
-     * @var int
-     */
-    public int $order;
-    /**
-     * One for current version and >1 for historical company names
-     *
-     * @var int
+     * One for current version and >1 for historical company forms
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate = '';
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
     public ?string $endDate = null;
+
     /**
      * Bankruptcy, liquidation or restructuring proceedings
-     *
-     * @var string
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
     public ?string $language = null;
 
-    public string $type;
+    /**
+     * Type of liquidation
+     */
+    public string $type = "";
 }
diff --git a/src/Dto/BisCompanyName.php b/src/Dto/BisCompanyName.php
index 0863b8d..836d238 100644
--- a/src/Dto/BisCompanyName.php
+++ b/src/Dto/BisCompanyName.php
@@ -18,38 +18,30 @@ class BisCompanyName extends DataTransferObject
      * Zero for primary company name,
      * other for translations of the primary company name
      * and auxiliary company names
-     *
-     * @var int
      */
     public int $order;
     /**
      * One for current version and >1 for historical company names
-     *
-     * @var int
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate = '';
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
     public ?string $endDate = null;
+
     /**
      * Company name
-     *
-     * @var string
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
     public ?string $language = null;
 }
diff --git a/src/Dto/BisCompanyRegisteredEntry.php b/src/Dto/BisCompanyRegisteredEntry.php
index 858b528..e870531 100644
--- a/src/Dto/BisCompanyRegisteredEntry.php
+++ b/src/Dto/BisCompanyRegisteredEntry.php
@@ -12,32 +12,26 @@ class BisCompanyRegisteredEntry extends DataTransferObject
 {
     /**
      * Description of entry
-     *
-     * @var string
      */
-    public string $description;
+    public string $description = "";
+
     /**
      * Zero for common entries, one for ‘Unregistered’ and two for ‘Registered’
-     *
-     * @see getStatusText()
-     *
-     * @var int
      */
     public int $status;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate;
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
-    public ?string $endDate;
+    public ?string $endDate = null;
+
     /**
-     * register (integer):
+     * register (int):
      * - One for Trade Register,
      * - two for Register of Foundations,
      * - three for Register of Associations,
@@ -48,18 +42,14 @@ class BisCompanyRegisteredEntry extends DataTransferObject
      * - eight for register of bodies liable for tax on insurance premiums
      *
      * @see getRegisterText()
-     *
-     * @var int
      */
     public int $register;
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
     public ?string $language;
     /**
-     * authority (integer):
+     * authority (int):
      * - One for Tax Administration,
      * - two for Finnish Patent and Registration Office and
      * - three for Population Register
@@ -74,35 +64,35 @@ class BisCompanyRegisteredEntry extends DataTransferObject
     {
         //  Zero for common entries, one for ‘Unregistered’ and two for ‘Registered’
         return match ($this->status) {
-            0 => 'Common',
-            1 => 'Unregistered',
-            2 => 'Registered',
-            default => throw new UnexpectedValueException('Unexpected value: ' . $this->status)
+            0 => "Common",
+            1 => "Unregistered",
+            2 => "Registered",
+            default => throw new UnexpectedValueException("Unexpected value: " . $this->status),
         };
     }
 
     public function getRegisterText(): string
     {
         return match ($this->register) {
-            1 => 'Trade Register',
-            2 => 'Register of Foundations',
-            3 => 'Register of Associations',
-            4 => 'Tax Administration',
-            5 => 'Prepayment Register',
-            6 => 'VAT Register',
-            7 => 'Employer Register',
-            8 => 'register of bodies liable for tax on insurance premiums',
-            default => throw new UnexpectedValueException('Unexpected value: ' . $this->register),
+            1 => "Trade Register",
+            2 => "Register of Foundations",
+            3 => "Register of Associations",
+            4 => "Tax Administration",
+            5 => "Prepayment Register",
+            6 => "VAT Register",
+            7 => "Employer Register",
+            8 => "register of bodies liable for tax on insurance premiums",
+            default => throw new UnexpectedValueException("Unexpected value: " . $this->register),
         };
     }
 
     public function getAuthorityText(): string
     {
         return match ($this->authority) {
-            1 => 'Tax Administration',
-            2 => 'Finnish Patent and Registration Office',
-            3 => 'Population Register',
-            default => throw new UnexpectedValueException('Unexpected value: ' . $this->authority),
+            1 => "Tax Administration",
+            2 => "Finnish Patent and Registration Office",
+            3 => "Population Register",
+            default => throw new UnexpectedValueException("Unexpected value: " . $this->authority),
         };
     }
 }
diff --git a/src/Dto/BisCompanyRegisteredOffice.php b/src/Dto/BisCompanyRegisteredOffice.php
index 1ae2845..0272b72 100644
--- a/src/Dto/BisCompanyRegisteredOffice.php
+++ b/src/Dto/BisCompanyRegisteredOffice.php
@@ -14,38 +14,31 @@ class BisCompanyRegisteredOffice extends DataTransferObject
 
     /**
      * Zero for primary place of registered office, positive for others
-     *
-     * @var int
      */
     public int $order;
+
     /**
      * One for current version and >1 for historical places of registered office
-     *
-     * @var int
      */
     public int $version;
+
     /**
      * Date of registration
-     *
-     * @var string
      */
-    public string $registrationDate;
+    public string $registrationDate = "";
+
     /**
      * Ending date of registration
-     *
-     * @var string|null
      */
-    public ?string $endDate;
+    public ?string $endDate = null;
+
     /**
      * Name of place of registered office
-     *
-     * @var string
      */
-    public string $name;
+    public string $name = "";
+
     /**
      * Two letter language code
-     *
-     * @var string|null
      */
-    public ?string $language;
+    public ?string $language = null;
 }