diff --git a/controller/documentTemplate/DocumentTemplateController.js b/controller/documentTemplate/DocumentTemplateController.js
index 7ade45d..40a2517 100644
--- a/controller/documentTemplate/DocumentTemplateController.js
+++ b/controller/documentTemplate/DocumentTemplateController.js
@@ -448,6 +448,73 @@ exports.updateTemplate = async (req, res) => {
   res.json(enriched);
 };
 
+// NEW: revise a template by creating a NEW template record (version bump) and deactivating the previous one.
+// Route suggestion: POST /document-templates/:id/revise (multipart/form-data with 'file')
+exports.reviseTemplate = async (req, res) => {
+  const previousId = req.params.id;
+  const { name, type, description, lang } = req.body;
+  const rawUserType = req.body.user_type || req.body.userType;
+  const rawContractType = req.body.contract_type || req.body.contractType;
+  const requestedState = req.body.state; // optional: 'active' | 'inactive'
+
+  const file = req.file;
+  if (!file) return res.status(400).json({ error: 'No file uploaded' });
+
+  const previous = await DocumentTemplateService.getTemplate(previousId);
+  if (!previous) return res.status(404).json({ error: 'Template not found' });
+
+  const nextType = type !== undefined ? type : previous.type;
+  const nextLang = lang !== undefined ? lang : previous.lang;
+  if (!nextLang || !['en', 'de'].includes(nextLang)) return res.status(400).json({ error: 'Invalid or missing language' });
+
+  const allowedUserTypes = ['personal', 'company', 'both'];
+  const user_type = allowedUserTypes.includes(rawUserType)
+    ? rawUserType
+    : (previous.user_type || 'both');
+
+  const allowedContractTypes = ['contract', 'gdpr'];
+  let contract_type = null;
+  if (nextType === 'contract') {
+    const candidate = rawContractType !== undefined ? rawContractType : previous.contract_type;
+    contract_type = allowedContractTypes.includes(candidate) ? candidate : 'contract';
+  }
+
+  // Use "english" for en, "german" for de
+  const langFolder = nextLang === 'en' ? 'english' : 'german';
+  const storageKey = `DocumentTemplates/${langFolder}/${Date.now()}_${file.originalname}`;
+
+  const s3 = new S3Client({
+    region: process.env.EXOSCALE_REGION,
+    endpoint: process.env.EXOSCALE_ENDPOINT,
+    credentials: {
+      accessKeyId: process.env.EXOSCALE_ACCESS_KEY,
+      secretAccessKey: process.env.EXOSCALE_SECRET_KEY
+    }
+  });
+  await s3.send(new PutObjectCommand({
+    Bucket: process.env.EXOSCALE_BUCKET,
+    Key: storageKey,
+    Body: file.buffer,
+    ContentType: file.mimetype
+  }));
+
+  const payload = {
+    name: name !== undefined ? name : previous.name,
+    type: nextType,
+    contract_type,
+    storageKey,
+    description: description !== undefined ? description : previous.description,
+    lang: nextLang,
+    user_type,
+    ...(requestedState !== undefined ? { state: requestedState } : {})
+  };
+
+  const created = await DocumentTemplateService.reviseTemplate(previousId, payload);
+  if (!created) return res.status(404).json({ error: 'Template not found' });
+  const enriched = await enrichTemplate(created, s3);
+  res.status(201).json(enriched);
+};
+
 exports.updateTemplateState = async (req, res) => {
   const id = req.params.id;
   const { state } = req.body;
diff --git a/repositories/template/DocumentTemplateRepository.js b/repositories/template/DocumentTemplateRepository.js
index 57774a5..5dd113e 100644
--- a/repositories/template/DocumentTemplateRepository.js
+++ b/repositories/template/DocumentTemplateRepository.js
@@ -28,21 +28,24 @@ class DocumentTemplateRepository {
       : null;
     const finalContractType = type === 'contract' ? (contract_type || 'contract') : null;
 
+    const version = Number.isFinite(Number(data.version)) ? Math.max(1, Number(data.version)) : 1;
+    const state = (data.state === 'active' || data.state === 'inactive') ? data.state : 'inactive';
+
     const query = `
       INSERT INTO document_templates (name, type, contract_type, storageKey, description, lang, user_type, version, state, createdAt, updatedAt)
-      VALUES (?, ?, ?, ?, ?, ?, ?, 1, 'inactive', NOW(), NOW())
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, NOW(), NOW())
     `;
     try {
       if (conn) {
-        const [res] = await conn.execute(query, [name, type, finalContractType, storageKey, description, lang, user_type]);
+        const [res] = await conn.execute(query, [name, type, finalContractType, storageKey, description, lang, user_type, version, state]);
         const insertId = res && (res.insertId || res[0]?.insertId);
         logger.info('DocumentTemplateRepository.create:success', { id: insertId || res.insertId });
-        return { id: insertId || res.insertId, name, type, contract_type: finalContractType, storageKey, description, lang, user_type, version: 1, state: 'inactive' };
+        return { id: insertId || res.insertId, name, type, contract_type: finalContractType, storageKey, description, lang, user_type, version, state };
       }
-      const result = await db.execute(query, [name, type, finalContractType, storageKey, description, lang, user_type]);
+      const result = await db.execute(query, [name, type, finalContractType, storageKey, description, lang, user_type, version, state]);
       const insertId = result && result.insertId ? result.insertId : (Array.isArray(result) && result[0] && result[0].insertId ? result[0].insertId : undefined);
       logger.info('DocumentTemplateRepository.create:success', { id: insertId });
-      return { id: insertId, name, type, contract_type: finalContractType, storageKey, description, lang, user_type, version: 1, state: 'inactive' };
+      return { id: insertId, name, type, contract_type: finalContractType, storageKey, description, lang, user_type, version, state };
     } catch (error) {
       logger.error('DocumentTemplateRepository.create:error', { error: error.message });
       throw error;
@@ -141,6 +144,55 @@ class DocumentTemplateRepository {
     }
   }
 
+  // Deactivate other active contract templates that would conflict with the one being activated.
+  // Conflict dimensions:
+  // - same type='contract'
+  // - same contract_type ('contract' | 'gdpr')
+  // - same lang
+  // - overlapping user_type (personal/company/both)
+  async deactivateOtherActiveContracts({ excludeId, contract_type, lang, user_type }, conn) {
+    logger.info('DocumentTemplateRepository.deactivateOtherActiveContracts:start', { excludeId, contract_type, lang, user_type });
+    const safeContractType = (contract_type === 'gdpr' || contract_type === 'contract') ? contract_type : 'contract';
+    const safeLang = (lang === 'en' || lang === 'de') ? lang : 'en';
+    const safeUserType = (user_type === 'personal' || user_type === 'company' || user_type === 'both') ? user_type : 'both';
+
+    // user_type overlap rules
+    const overlap = safeUserType === 'both'
+      ? ['personal', 'company', 'both']
+      : [safeUserType, 'both'];
+
+    const query = `
+      UPDATE document_templates
+      SET state = 'inactive', updatedAt = NOW()
+      WHERE id <> ?
+        AND type = 'contract'
+        AND (
+          contract_type = ?
+          OR (contract_type IS NULL AND ? = 'contract')
+        )
+        AND lang = ?
+        AND state = 'active'
+        AND (
+          user_type IN (${overlap.map(() => '?').join(', ')})
+          OR user_type IS NULL
+        )
+    `;
+    const params = [excludeId, safeContractType, safeContractType, safeLang, ...overlap];
+    try {
+      if (conn) {
+        const [res] = await conn.execute(query, params);
+        logger.info('DocumentTemplateRepository.deactivateOtherActiveContracts:success', { affected: res?.affectedRows });
+        return res?.affectedRows || 0;
+      }
+      const res = await db.execute(query, params);
+      logger.info('DocumentTemplateRepository.deactivateOtherActiveContracts:success', { affected: res?.affectedRows });
+      return res?.affectedRows || 0;
+    } catch (error) {
+      logger.error('DocumentTemplateRepository.deactivateOtherActiveContracts:error', { error: error.message });
+      throw error;
+    }
+  }
+
   async delete(id, conn) {
     logger.info('DocumentTemplateRepository.delete:start', { id });
     const query = `DELETE FROM document_templates WHERE id = ?`;
diff --git a/routes/postRoutes.js b/routes/postRoutes.js
index c4b214d..9ca2c60 100644
--- a/routes/postRoutes.js
+++ b/routes/postRoutes.js
@@ -59,6 +59,7 @@ router.post('/permissions', authMiddleware, PermissionController.create);
 
 // Document templates upload & signature generation POSTs (moved)
 router.post('/document-templates', authMiddleware, upload.single('file'), DocumentTemplateController.uploadTemplate);
+router.post('/document-templates/:id/revise', authMiddleware, upload.single('file'), DocumentTemplateController.reviseTemplate);
 router.post('/document-templates/:id/generate-pdf-with-signature', authMiddleware, DocumentTemplateController.generatePdfWithSignature);
 
 // Document uploads (moved from routes/documents.js)
diff --git a/services/template/DocumentTemplateService.js b/services/template/DocumentTemplateService.js
index 65003a2..351066b 100644
--- a/services/template/DocumentTemplateService.js
+++ b/services/template/DocumentTemplateService.js
@@ -116,7 +116,25 @@ class DocumentTemplateService {
     const uow = new UnitOfWork();
     try {
       await uow.start();
+      const current = await DocumentTemplateRepository.findById(id, uow.connection);
+      if (!current) {
+        logger.warn('DocumentTemplateService.updateTemplateState:not_found', { id });
+        await uow.rollback();
+        return null;
+      }
+
       await DocumentTemplateRepository.updateState(id, state, uow.connection);
+
+      // Enforce singleton active template per (contract_type + lang + overlapping user scope)
+      if (state === 'active' && current.type === 'contract') {
+        await DocumentTemplateRepository.deactivateOtherActiveContracts({
+          excludeId: id,
+          contract_type: current.contract_type || 'contract',
+          lang: current.lang,
+          user_type: current.user_type || 'both'
+        }, uow.connection);
+      }
+
       const updated = await DocumentTemplateRepository.findById(id, uow.connection);
       await uow.commit();
       logger.info('DocumentTemplateService.updateTemplateState:success', { id, state });
@@ -128,6 +146,59 @@ class DocumentTemplateService {
     }
   }
 
+  // NEW: Create a new template as a revision of an existing one.
+  // - New record is created with version = previous.version + 1
+  // - Previous record is deactivated (state -> inactive)
+  // - New record state defaults to previous state (active stays active, inactive stays inactive)
+  async reviseTemplate(previousId, data) {
+    logger.info('DocumentTemplateService.reviseTemplate:start', { previousId });
+    const uow = new UnitOfWork();
+    try {
+      await uow.start();
+      const previous = await DocumentTemplateRepository.findById(previousId, uow.connection);
+      if (!previous) {
+        logger.warn('DocumentTemplateService.reviseTemplate:not_found', { previousId });
+        await uow.rollback();
+        return null;
+      }
+
+      const nextVersion = (previous.version || 1) + 1;
+      const nextState = (data.state === 'active' || data.state === 'inactive')
+        ? data.state
+        : (previous.state === 'active' ? 'active' : 'inactive');
+
+      const created = await DocumentTemplateRepository.create(
+        {
+          ...data,
+          version: nextVersion,
+          state: nextState,
+        },
+        uow.connection
+      );
+
+      // If new template is active and is a contract template, deactivate other conflicting actives
+      if (nextState === 'active' && (data.type === 'contract' || previous.type === 'contract')) {
+        await DocumentTemplateRepository.deactivateOtherActiveContracts({
+          excludeId: created.id,
+          contract_type: (data.contract_type || previous.contract_type || 'contract'),
+          lang: (data.lang || previous.lang),
+          user_type: (data.user_type || previous.user_type || 'both')
+        }, uow.connection);
+      }
+
+      // Deactivate previous (requirement: deactive the previous one)
+      await DocumentTemplateRepository.updateState(previousId, 'inactive', uow.connection);
+
+      await uow.commit();
+      logger.info('DocumentTemplateService.reviseTemplate:success', { previousId, newId: created.id, version: nextVersion });
+      return created;
+    } catch (err) {
+      logger.error('DocumentTemplateService.reviseTemplate:error', { previousId, error: err.message });
+      await uow.rollback(err);
+      throw err;
+    }
+  }
+
   async getActiveTemplatesForUserType(userType, templateType = null, contractType = null) {
     logger.info('DocumentTemplateService.getActiveTemplatesForUserType:start', { userType, templateType, contractType });
     try {