diff --git a/apps/dav/lib/CalDAV/Federation/CalendarFederationConfig.php b/apps/dav/lib/CalDAV/Federation/CalendarFederationConfig.php
index b7293bad9fa9f..cfbbbe029e6de 100644
--- a/apps/dav/lib/CalDAV/Federation/CalendarFederationConfig.php
+++ b/apps/dav/lib/CalDAV/Federation/CalendarFederationConfig.php
@@ -9,15 +9,36 @@
 
 namespace OCA\DAV\CalDAV\Federation;
 
-use OCP\AppFramework\Services\IAppConfig;
+use OCP\IAppConfig;
 
 class CalendarFederationConfig {
 	public function __construct(
 		private readonly IAppConfig $appConfig,
+		private \OCP\GlobalScale\IConfig $gsConfig,
 	) {
 	}
 
 	public function isFederationEnabled(): bool {
-		return $this->appConfig->getAppValueBool('enableCalendarFederation', true);
+		return $this->appConfig->getValueBool('dav', 'enableCalendarFederation', true);
+	}
+
+	/**
+	 * Check if users are allowed to create federated shares
+	 */
+	public function isOutgoingServer2serverShareEnabled(): bool {
+		if ($this->gsConfig->onlyInternalFederation()) {
+			return false;
+		}
+		return $this->appConfig->getValueBool('files_sharing', 'outgoing_server2server_share_enabled', true);
+	}
+
+	/**
+	 * Check if users are allowed to receive federated shares
+	 */
+	public function isIncomingServer2serverShareEnabled(): bool {
+		if ($this->gsConfig->onlyInternalFederation()) {
+			return false;
+		}
+		return $this->appConfig->getValueBool('files_sharing', 'incoming_server2server_share_enabled', true);
 	}
 }
diff --git a/apps/dav/lib/CalDAV/Federation/CalendarFederationProvider.php b/apps/dav/lib/CalDAV/Federation/CalendarFederationProvider.php
index 348852fb9310d..3a13c5886d0dc 100644
--- a/apps/dav/lib/CalDAV/Federation/CalendarFederationProvider.php
+++ b/apps/dav/lib/CalDAV/Federation/CalendarFederationProvider.php
@@ -55,6 +55,15 @@ public function shareReceived(ICloudFederationShare $share): string {
 			);
 		}
 
+		if (!$this->calendarFederationConfig->isIncomingServer2serverShareEnabled()) {
+			$this->logger->debug('Received a federated calendar share which is not allowed on this instance');
+			throw new ProviderCouldNotAddShareException(
+				'Instance does not support receiving federated calendar shares',
+				'',
+				Http::STATUS_SERVICE_UNAVAILABLE,
+			);
+		}
+
 		if (!in_array($share->getShareType(), $this->getSupportedShareTypes(), true)) {
 			$this->logger->debug('Received a federation invite for invalid share type');
 			throw new ProviderCouldNotAddShareException(
diff --git a/apps/dav/lib/CalDAV/Federation/FederationSharingService.php b/apps/dav/lib/CalDAV/Federation/FederationSharingService.php
index 57df75b01a077..3ac9148b2a9c5 100644
--- a/apps/dav/lib/CalDAV/Federation/FederationSharingService.php
+++ b/apps/dav/lib/CalDAV/Federation/FederationSharingService.php
@@ -34,6 +34,7 @@ public function __construct(
 		private readonly LoggerInterface $logger,
 		private readonly ISecureRandom $random,
 		private readonly SharingMapper $sharingMapper,
+		private readonly CalendarFederationConfig $config,
 	) {
 	}
 
@@ -70,6 +71,14 @@ private function decodeRemoteUserPrincipal(string $principal): ?string {
 	public function shareWith(IShareable $shareable, string $principal, int $access): void {
 		$baseError = 'Failed to create federated calendar share: ';
 
+		if (!$this->config->isOutgoingServer2serverShareEnabled()) {
+			$this->logger->error('cannot share with remote user because federated sharing is disabled on this instance', [
+				'shareable' => $shareable->getName(),
+				'encodedShareWith' => $principal,
+			]);
+			return;
+		}
+
 		// 1. Validate share data
 		$shareWith = $this->decodeRemoteUserPrincipal($principal);
 		if ($shareWith === null) {
diff --git a/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationConfigTest.php b/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationConfigTest.php
index b8b37eea16748..845a4ade77cc0 100644
--- a/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationConfigTest.php
+++ b/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationConfigTest.php
@@ -10,7 +10,8 @@
 namespace OCA\DAV\Tests\unit\CalDAV\Federation;
 
 use OCA\DAV\CalDAV\Federation\CalendarFederationConfig;
-use OCP\AppFramework\Services\IAppConfig;
+use OCP\GlobalScale\IConfig;
+use OCP\IAppConfig;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\MockObject\MockObject;
 use Test\TestCase;
@@ -19,14 +20,17 @@ class CalendarFederationConfigTest extends TestCase {
 	private CalendarFederationConfig $config;
 
 	private IAppConfig&MockObject $appConfig;
+	private IConfig&MockObject $gsConfig;
 
 	protected function setUp(): void {
 		parent::setUp();
 
 		$this->appConfig = $this->createMock(IAppConfig::class);
+		$this->gsConfig = $this->createMock(IConfig::class);
 
 		$this->config = new CalendarFederationConfig(
 			$this->appConfig,
+			$this->gsConfig,
 		);
 	}
 
@@ -40,10 +44,74 @@ public static function provideIsFederationEnabledData(): array {
 	#[DataProvider(methodName: 'provideIsFederationEnabledData')]
 	public function testIsFederationEnabled(bool $configValue): void {
 		$this->appConfig->expects(self::once())
-			->method('getAppValueBool')
-			->with('enableCalendarFederation', true)
+			->method('getValueBool')
+			->with('dav', 'enableCalendarFederation', true)
 			->willReturn($configValue);
 
 		$this->assertEquals($configValue, $this->config->isFederationEnabled());
 	}
+
+	public static function provideIsOutgoingServer2serverShareEnabledData(): array {
+		return [
+			[false, false, false],
+			[false, true, true],
+			[true, false, false],
+			[true, false, false],
+		];
+	}
+
+	#[DataProvider(methodName: 'provideIsOutgoingServer2serverShareEnabledData')]
+	public function testIsOutgoingServer2serverShareEnabled(
+		bool $globalScaleEnabled,
+		bool $expected,
+		bool $configValue,
+	): void {
+		$this->gsConfig->expects(self::once())
+			->method('onlyInternalFederation')
+			->willReturn($globalScaleEnabled);
+
+		if (!$globalScaleEnabled) {
+			$this->appConfig->expects(self::once())
+				->method('getValueBool')
+				->with('files_sharing', 'outgoing_server2server_share_enabled', true)
+				->willReturn($configValue);
+		} else {
+			$this->appConfig->expects(self::never())
+				->method('getValueBool');
+		}
+
+		$this->assertEquals($expected, $this->config->isOutgoingServer2serverShareEnabled());
+	}
+
+	public static function provideIsIncomingServer2serverShareEnabledData(): array {
+		return [
+			[false, false, false],
+			[false, true, true],
+			[true, false, false],
+			[true, false, true],
+		];
+	}
+
+	#[DataProvider(methodName: 'provideIsIncomingServer2serverShareEnabledData')]
+	public function testIsIncomingServer2serverShareEnabled(
+		bool $globalScaleEnabled,
+		bool $expected,
+		bool $configValue,
+	): void {
+		$this->gsConfig->expects(self::once())
+			->method('onlyInternalFederation')
+			->willReturn($globalScaleEnabled);
+
+		if (!$globalScaleEnabled) {
+			$this->appConfig->expects(self::once())
+				->method('getValueBool')
+				->with('files_sharing', 'incoming_server2server_share_enabled', true)
+				->willReturn($configValue);
+		} else {
+			$this->appConfig->expects(self::never())
+				->method('getValueBool');
+		}
+
+		$this->assertEquals($expected, $this->config->isIncomingServer2serverShareEnabled());
+	}
 }
diff --git a/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationProviderTest.php b/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationProviderTest.php
index 6e6577b24fa13..24ffec58343e6 100644
--- a/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationProviderTest.php
+++ b/apps/dav/tests/unit/CalDAV/Federation/CalendarFederationProviderTest.php
@@ -91,6 +91,10 @@ public function testShareReceived(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::once())
 			->method('findByUri')
 			->with(
@@ -150,6 +154,10 @@ public function testShareReceivedWithExistingCalendar(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$existingCalendar = new FederatedCalendarEntity();
 		$existingCalendar->setId(10);
 		$existingCalendar->setPrincipaluri('principals/users/sharee1');
@@ -204,6 +212,10 @@ public function testShareReceivedWithInvalidProtocolVersion(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::never())
 			->method('insert');
 		$this->jobList->expects(self::never())
@@ -232,6 +244,10 @@ public function testShareReceivedWithoutProtocolVersion(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::never())
 			->method('insert');
 		$this->jobList->expects(self::never())
@@ -261,6 +277,30 @@ public function testShareReceivedWithDisabledConfig(): void {
 		$this->calendarFederationProvider->shareReceived($share);
 	}
 
+	public function testShareReceivedWithIncomingServer2serverShareDisabled(): void {
+		$share = $this->createMock(ICloudFederationShare::class);
+		$share->method('getShareType')
+			->willReturn('user');
+
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isFederationEnabled')
+			->willReturn(true);
+
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(false);
+
+		$this->federatedCalendarMapper->expects(self::never())
+			->method('insert');
+		$this->jobList->expects(self::never())
+			->method('add');
+
+		$this->expectException(ProviderCouldNotAddShareException::class);
+		$this->expectExceptionMessage('Instance does not support receiving federated calendar shares');
+		$this->expectExceptionCode(503);
+		$this->calendarFederationProvider->shareReceived($share);
+	}
+
 	public function testShareReceivedWithUnsupportedShareType(): void {
 		$share = $this->createMock(ICloudFederationShare::class);
 		$share->method('getShareType')
@@ -270,6 +310,10 @@ public function testShareReceivedWithUnsupportedShareType(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::never())
 			->method('insert');
 		$this->jobList->expects(self::never())
@@ -322,6 +366,10 @@ public function testShareReceivedWithIncompleteProtocolData(array $protocol): vo
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::never())
 			->method('insert');
 		$this->jobList->expects(self::never())
@@ -359,6 +407,10 @@ public function testShareReceivedWithReadWriteAccess(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::once())
 			->method('findByUri')
 			->with(
@@ -418,6 +470,10 @@ public function testShareReceivedWithUnsupportedAccess(): void {
 			->method('isFederationEnabled')
 			->willReturn(true);
 
+		$this->calendarFederationConfig->expects(self::once())
+			->method('isIncomingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->federatedCalendarMapper->expects(self::never())
 			->method('insert');
 		$this->jobList->expects(self::never())
diff --git a/apps/dav/tests/unit/CalDAV/Federation/FederationSharingServiceTest.php b/apps/dav/tests/unit/CalDAV/Federation/FederationSharingServiceTest.php
index 6df0a565c938b..9a1ae90cf8e04 100644
--- a/apps/dav/tests/unit/CalDAV/Federation/FederationSharingServiceTest.php
+++ b/apps/dav/tests/unit/CalDAV/Federation/FederationSharingServiceTest.php
@@ -10,6 +10,7 @@
 namespace OCA\DAV\Tests\unit\CalDAV\Federation;
 
 use OCA\DAV\CalDAV\Calendar;
+use OCA\DAV\CalDAV\Federation\CalendarFederationConfig;
 use OCA\DAV\CalDAV\Federation\FederationSharingService;
 use OCA\DAV\DAV\Sharing\IShareable;
 use OCA\DAV\DAV\Sharing\SharingMapper;
@@ -38,6 +39,7 @@ class FederationSharingServiceTest extends TestCase {
 	private readonly LoggerInterface&MockObject $logger;
 	private readonly ISecureRandom&MockObject $random;
 	private readonly SharingMapper&MockObject $sharingMapper;
+	private readonly CalendarFederationConfig&MockObject $config;
 
 	protected function setUp(): void {
 		parent::setUp();
@@ -49,6 +51,7 @@ protected function setUp(): void {
 		$this->logger = $this->createMock(LoggerInterface::class);
 		$this->random = $this->createMock(ISecureRandom::class);
 		$this->sharingMapper = $this->createMock(SharingMapper::class);
+		$this->config = $this->createMock(CalendarFederationConfig::class);
 
 		$this->federationSharingService = new FederationSharingService(
 			$this->federationManager,
@@ -58,6 +61,7 @@ protected function setUp(): void {
 			$this->logger,
 			$this->random,
 			$this->sharingMapper,
+			$this->config,
 		);
 	}
 
@@ -83,6 +87,10 @@ public function testShareWith(): void {
 				]
 			});
 
+		$this->config->expects(self::once())
+			->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$hostUser = $this->createMock(IUser::class);
 		$hostUser->method('getCloudId')
 			->willReturn('host1@nextcloud.host');
@@ -195,6 +203,10 @@ public function testShareWithWithFailingFederationManager(): void {
 				]
 			});
 
+		$this->config->expects(self::once())
+			->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$hostUser = $this->createMock(IUser::class);
 		$hostUser->method('getCloudId')
 			->willReturn('host1@nextcloud.host');
@@ -299,6 +311,10 @@ public function testShareWithWithUnsuccessfulResponse(): void {
 				]
 			});
 
+		$this->config->expects(self::once())
+			->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$hostUser = $this->createMock(IUser::class);
 		$hostUser->method('getCloudId')
 			->willReturn('host1@nextcloud.host');
@@ -381,6 +397,34 @@ public function testShareWithWithUnsuccessfulResponse(): void {
 		);
 	}
 
+	public function testShareWithWithOutgoingServer2serverShareDisabled(): void {
+		$shareable = $this->createMock(Calendar::class);
+		$shareable->method('getOwner')
+			->willReturn('principals/users/host1');
+		$shareable->method('getName')
+			->willReturn('cal1');
+
+		$this->config->expects(self::once())
+			->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(false);
+
+		$this->userManager->expects(self::never())
+			->method('get');
+
+		$this->federationManager->expects(self::never())
+			->method('sendCloudShare');
+		$this->sharingMapper->expects(self::never())
+			->method('deleteShare');
+		$this->sharingMapper->expects(self::never())
+			->method('shareWithToken');
+
+		$this->federationSharingService->shareWith(
+			$shareable,
+			'principals/remote-users/cmVtb3RlMUBuZXh0Y2xvdWQucmVtb3Rl',
+			3, // Read-only
+		);
+	}
+
 	public static function provideInvalidRemoteUserPrincipalData(): array {
 		return [
 			['principals/users/foobar'],
@@ -418,6 +462,9 @@ public function testShareWithWithUnknownUser(): void {
 		$shareable->method('getOwner')
 			->willReturn('principals/users/host1');
 
+		$this->config->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->userManager->expects(self::once())
 			->method('get')
 			->with('host1')
@@ -442,6 +489,9 @@ public function testShareWithWithInvalidShareable(): void {
 		$shareable->method('getOwner')
 			->willReturn('principals/users/host1');
 
+		$this->config->method('isOutgoingServer2serverShareEnabled')
+			->willReturn(true);
+
 		$this->userManager->expects(self::once())
 			->method('get')
 			->with('host1')