diff --git a/lib/Errors/NotFoundException.php b/lib/Errors/NotFoundException.php
new file mode 100644
index 0000000..8a41e65
--- /dev/null
+++ b/lib/Errors/NotFoundException.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace OCA\OrganizationFolders\Errors;
+
+abstract class NotFoundException extends \RuntimeException {
+	public function __construct($entity, array|string $criteria) {
+		$message = sprintf(
+			"Could not find %s with criteria %s",
+			class_exists($entity) ? array_pop(explode('\\', $entity)) : $entity,
+			is_string($criteria) ? $criteria : json_encode($criteria),
+		);
+		parent::__construct($message);
+	}
+}
diff --git a/lib/Errors/OrganizationNotFound.php b/lib/Errors/OrganizationNotFound.php
new file mode 100644
index 0000000..5d1d376
--- /dev/null
+++ b/lib/Errors/OrganizationNotFound.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace OCA\OrganizationFolders\Errors;
+
+class OrganizationNotFound extends NotFoundException {
+    public function __construct($provider, $id) {
+		parent::__construct(OCA\OrganizationFolders\Model\Organization::class, ["provider" => $provider, "id" => $id]);
+	}
+}
\ No newline at end of file
diff --git a/lib/Errors/OrganizationRoleNotFound.php b/lib/Errors/OrganizationRoleNotFound.php
new file mode 100644
index 0000000..baa3021
--- /dev/null
+++ b/lib/Errors/OrganizationRoleNotFound.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace OCA\OrganizationFolders\Errors;
+
+class OrganizationRoleNotFound extends NotFoundException {
+    public function __construct($provider, $id) {
+		parent::__construct(OCA\OrganizationFolders\Model\OrganizationRole::class, ["provider" => $provider, "id" => $id]);
+	}
+}
\ No newline at end of file
diff --git a/lib/Events/RegisterOrganisationProviderEvent.php b/lib/Events/RegisterOrganizationProviderEvent.php
similarity index 89%
rename from lib/Events/RegisterOrganisationProviderEvent.php
rename to lib/Events/RegisterOrganizationProviderEvent.php
index 3675050..b3e6bb2 100644
--- a/lib/Events/RegisterOrganisationProviderEvent.php
+++ b/lib/Events/RegisterOrganizationProviderEvent.php
@@ -6,7 +6,7 @@ namespace OCA\OrganizationFolders\Events;
 
 use OCP\EventDispatcher\Event;
 
-use OCA\OrganizationFolders\Transport\OrganizationProviderManager;
+use OCA\OrganizationFolders\OrganizationProvider\OrganizationProviderManager;
 
 /**
  * This event is triggered during the initialization of Organization Folders.
diff --git a/lib/OrganisationProvider/OrganizationProvider.php b/lib/OrganizationProvider/OrganizationProvider.php
similarity index 92%
rename from lib/OrganisationProvider/OrganizationProvider.php
rename to lib/OrganizationProvider/OrganizationProvider.php
index 9266a84..0f8f8b7 100644
--- a/lib/OrganisationProvider/OrganizationProvider.php
+++ b/lib/OrganizationProvider/OrganizationProvider.php
@@ -7,6 +7,9 @@ namespace OCA\OrganizationFolders\OrganizationProvider;
 use OCA\OrganizationFolders\Model\Organization;
 use OCA\OrganizationFolders\Model\OrganizationRole;
 
+use OCA\OrganizationFolders\Errors\OrganizationNotFound;
+use OCA\OrganizationFolders\Errors\OrganizationRoleNotFound;
+
 abstract class OrganizationProvider {
 	protected $id;
 
@@ -17,6 +20,7 @@ abstract class OrganizationProvider {
    /**
     * Get specific role by its id (unique within OrganizationProvider)
     * @return Organization
+    * @throws OrganizationNotFound
     */
 	abstract public function getOrganization(int $id): Organization;
 
@@ -56,9 +60,10 @@ abstract class OrganizationProvider {
 	abstract public function getSubOrganizations(?int $parentOrganizationId): array;
 
    /**
-    * Get specific role by its id (unique within OrganizationProvider)
+    * Get a specific role by its id (must be unique within organization provider, not just within parent organization)
     *
     * @return OrganizationRole
+    * @throws OrganizationRoleNotFound
     */
     abstract public function getRole(int $id): OrganizationRole;
 
diff --git a/lib/OrganisationProvider/OrganizationProviderManager.php b/lib/OrganizationProvider/OrganizationProviderManager.php
similarity index 86%
rename from lib/OrganisationProvider/OrganizationProviderManager.php
rename to lib/OrganizationProvider/OrganizationProviderManager.php
index f33af90..91cbb42 100644
--- a/lib/OrganisationProvider/OrganizationProviderManager.php
+++ b/lib/OrganizationProvider/OrganizationProviderManager.php
@@ -26,6 +26,13 @@ class OrganizationProviderManager {
 		return $this->organizationProviders;
 	}
 
+	/**
+	 * @return bool
+	 */
+	public function hasOrganizationProvider($id): bool {
+		return array_key_exists($id, $this->organizationProviders);
+	}
+
 	/**
 	 * @return OrganizationProvider
 	 */