diff --git a/lib/Helper/ValidateHelper.php b/lib/Helper/ValidateHelper.php
index ac4b1d55e8..39bd95b9ba 100644
--- a/lib/Helper/ValidateHelper.php
+++ b/lib/Helper/ValidateHelper.php
@@ -125,6 +125,17 @@ public function validateFile(array $data, int $type = self::TYPE_TO_SIGN, ?IUser
 			}
 			$this->validateIfNodeIdExists((int)$data['file']['fileId'], $data['userManager']->getUID(), $type);
 			$this->validateMimeTypeAcceptedByNodeId((int)$data['file']['fileId'], $data['userManager']->getUID(), $type);
+		} elseif (!empty($data['file']['nodeId'])) {
+			if (!is_numeric($data['file']['nodeId'])) {
+				throw new LibresignException($this->l10n->t('File type: %s. Invalid fileID.', [$this->getTypeOfFile($type)]));
+			}
+			if (!is_a($user, IUser::class)) {
+				if (!isset($data['userManager']) || !is_a($data['userManager'], IUser::class)) {
+					throw new LibresignException($this->l10n->t('User not found.'));
+				}
+			}
+			$this->validateIfNodeIdExists((int)$data['file']['nodeId'], $data['userManager']->getUID(), $type);
+			$this->validateMimeTypeAcceptedByNodeId((int)$data['file']['nodeId'], $data['userManager']->getUID(), $type);
 		} elseif (!empty($data['file']['base64'])) {
 			$this->validateBase64($data['file']['base64'], $type);
 		} elseif (!empty($data['file']['path'])) {
diff --git a/lib/Service/FileService.php b/lib/Service/FileService.php
index be8211173a..2a5fca7151 100644
--- a/lib/Service/FileService.php
+++ b/lib/Service/FileService.php
@@ -115,6 +115,9 @@ public function getNodeFromData(array $data): Node {
 		if (isset($data['file']['path'])) {
 			return $this->folderService->getFileByPath($data['file']['path']);
 		}
+		if (isset($data['file']['nodeId'])) {
+			return $this->folderService->getFileByNodeId($data['file']['nodeId']);
+		}
 
 		$content = $this->getFileRaw($data);
 		$extension = $this->getExtension($content);
diff --git a/tests/php/Unit/Helper/ValidateHelperTest.php b/tests/php/Unit/Helper/ValidateHelperTest.php
index 7b29c6bff8..28f2aface7 100644
--- a/tests/php/Unit/Helper/ValidateHelperTest.php
+++ b/tests/php/Unit/Helper/ValidateHelperTest.php
@@ -135,6 +135,47 @@ public function testValidateNewFileUsingFileIdWithSuccess():void {
 		$this->assertNull($actual);
 	}
 
+	public function testValidateNewFileUsingNodeIdWithSuccess():void {
+		$file = $this->createMock(\OCP\Files\File::class);
+		$file
+			->method('getMimeType')
+			->willReturn('application/pdf');
+		$this->root
+			->method('getUserFolder')
+			->willReturn($this->root);
+		$this->root
+			->method('getFirstNodeById')
+			->willReturn($file);
+
+		$user = $this->createMock(\OCP\IUser::class);
+		$user->method('getUID')->willReturn('john.doe');
+		$actual = $this->getValidateHelper()->validateNewFile([
+			'file' => ['nodeId' => 35523],
+			'name' => 'test',
+			'userManager' => $user,
+		]);
+		$this->assertNull($actual);
+	}
+
+	public function testValidateFileWithInvalidNodeId():void {
+		$this->expectExceptionMessage('Invalid fileID');
+		$user = $this->createMock(\OCP\IUser::class);
+		$user->method('getUID')->willReturn('john.doe');
+		$this->getValidateHelper()->validateFile([
+			'file' => ['nodeId' => 'invalid'],
+			'name' => 'test',
+			'userManager' => $user,
+		]);
+	}
+
+	public function testValidateFileWithNodeIdWithoutUser():void {
+		$this->expectExceptionMessage('User not found');
+		$this->getValidateHelper()->validateFile([
+			'file' => ['nodeId' => 35523],
+			'name' => 'test',
+		]);
+	}
+
 	public function testValidateNotRequestedSignWhenAlreadyAskedToSignThisDocument():void {
 		$this->signRequestMapper->method('getByNodeId')->willReturn('exists');
 		$this->expectExceptionMessage('Already asked to sign this document');
diff --git a/tests/php/Unit/Service/FileServiceTest.php b/tests/php/Unit/Service/FileServiceTest.php
index 62fdf48b69..c8324f0109 100644
--- a/tests/php/Unit/Service/FileServiceTest.php
+++ b/tests/php/Unit/Service/FileServiceTest.php
@@ -88,4 +88,76 @@ public function testSetFileByIdSetsFile(): void {
 		$this->assertInstanceOf(FileService::class, $returned);
 		$this->assertSame(1, $service->getStatus());
 	}
+
+	public function testGetNodeFromDataWithNodeId(): void {
+		$node = $this->createMock(\OCP\Files\File::class);
+		$folderService = $this->createMock(\OCA\Libresign\Service\FolderService::class);
+		$folderService->method('getUserId')->willReturn('testuser');
+		$folderService->method('getFileByNodeId')->with(35523)->willReturn($node);
+
+		$userManager = $this->createMock(\OCP\IUser::class);
+		$userManager->method('getUID')->willReturn('testuser');
+
+		$service = $this->createFileService([
+			\OCA\Libresign\Service\FolderService::class => $folderService,
+		]);
+
+		$data = [
+			'file' => ['nodeId' => 35523],
+			'userManager' => $userManager,
+		];
+
+		$result = $service->getNodeFromData($data);
+		$this->assertSame($node, $result);
+	}
+
+	public function testGetNodeFromDataWithFileId(): void {
+		$node = $this->createMock(\OCP\Files\File::class);
+		$folderService = $this->createMock(\OCA\Libresign\Service\FolderService::class);
+		$folderService->method('getUserId')->willReturn('testuser');
+		$folderService->method('getFileByNodeId')->with(12345)->willReturn($node);
+
+		$userManager = $this->createMock(\OCP\IUser::class);
+		$userManager->method('getUID')->willReturn('testuser');
+
+		$service = $this->createFileService([
+			\OCA\Libresign\Service\FolderService::class => $folderService,
+		]);
+
+		$data = [
+			'file' => ['fileId' => 12345],
+			'userManager' => $userManager,
+		];
+
+		$result = $service->getNodeFromData($data);
+		$this->assertSame($node, $result);
+	}
+
+	public function testGetNodeFromDataPrefersFileIdOverNodeId(): void {
+		$nodeFromFileId = $this->createMock(\OCP\Files\File::class);
+		$folderService = $this->createMock(\OCA\Libresign\Service\FolderService::class);
+		$folderService->method('getUserId')->willReturn('testuser');
+		$folderService->expects($this->once())
+			->method('getFileByNodeId')
+			->with(12345)
+			->willReturn($nodeFromFileId);
+
+		$userManager = $this->createMock(\OCP\IUser::class);
+		$userManager->method('getUID')->willReturn('testuser');
+
+		$service = $this->createFileService([
+			\OCA\Libresign\Service\FolderService::class => $folderService,
+		]);
+
+		$data = [
+			'file' => [
+				'fileId' => 12345,
+				'nodeId' => 35523, // This should be ignored
+			],
+			'userManager' => $userManager,
+		];
+
+		$result = $service->getNodeFromData($data);
+		$this->assertSame($nodeFromFileId, $result);
+	}
 }