diff --git a/api-v3/src/database/migrations/1790087250000-f5-operational-context-compatibility.ts b/api-v3/src/database/migrations/1790087250000-f5-operational-context-compatibility.ts
index 2643f5c..db0032a 100644
--- a/api-v3/src/database/migrations/1790087250000-f5-operational-context-compatibility.ts
+++ b/api-v3/src/database/migrations/1790087250000-f5-operational-context-compatibility.ts
@@ -1,22 +1,92 @@
 import { MigrationInterface, QueryRunner } from 'typeorm';
 
 /**
- * F5 keeps operator_company_id only as a compatibility/current-context snapshot.
- * It is NOT part of the physical hierarchy; Area↔Company temporal truth lives in
- * area_company_relations. Runtime membership is resolved by Area ancestry.
+ * F5 makes the physical hierarchy Area-owned. Empresa is never a parent nor a
+ * required property of Yacimiento/Instalación/Subinstalación. The current and
+ * historical operator/concession truth lives in area_company_relations and is
+ * frozen separately by each Inspección/Acta.
+ *
+ * operator_company_id is tolerated only on pre-F5 rows for backwards-readable
+ * history. New assignments or changes are rejected by the DB guard.
  */
 export class F5OperationalContextCompatibility1790087250000 implements MigrationInterface {
   name = 'F5OperationalContextCompatibility1790087250000';
 
   public async up(queryRunner: QueryRunner): Promise<void> {
-    await this.installCompatibilityGuard(queryRunner);
-  }
-
-  public async down(queryRunner: QueryRunner): Promise<void> {
     await this.installAreaOwnedGuard(queryRunner);
   }
 
-  private async installCompatibilityGuard(queryRunner: QueryRunner): Promise<void> {
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await this.installLegacyPairedGuard(queryRunner);
+  }
+
+  private async installAreaOwnedGuard(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      CREATE OR REPLACE FUNCTION enforce_asset_operational_context()
+      RETURNS trigger LANGUAGE plpgsql AS $$
+      DECLARE
+        asset_role asset_type_operational_role;
+        area_role asset_type_operational_role;
+      BEGIN
+        SELECT operational_role INTO asset_role
+        FROM asset_types WHERE id=NEW.asset_type_id;
+
+        IF asset_role <> 'GENERIC'::asset_type_operational_role THEN
+          IF NEW.operational_area_id IS NOT NULL OR NEW.operator_company_id IS NOT NULL THEN
+            RAISE EXCEPTION USING ERRCODE='23514',
+              MESSAGE='Área y Empresa no reciben contexto operativo de Inventario';
+          END IF;
+          RETURN NEW;
+        END IF;
+
+        -- Historical rows may still contain the old operator snapshot. It remains
+        -- readable, but F5 never creates or changes that ownership-like value.
+        IF NEW.operator_company_id IS NOT NULL THEN
+          IF TG_OP='INSERT'
+             OR OLD.operator_company_id IS NULL
+             OR NEW.operator_company_id IS DISTINCT FROM OLD.operator_company_id THEN
+            RAISE EXCEPTION USING ERRCODE='23514',
+              MESSAGE='La Empresa pertenece al contexto temporal del Área/Inspección y no al Inventario';
+          END IF;
+        END IF;
+
+        IF NEW.operational_area_id IS NULL THEN
+          RETURN NEW;
+        END IF;
+
+        SELECT t.operational_role INTO area_role
+        FROM assets area
+        JOIN asset_types t ON t.id=area.asset_type_id
+        WHERE area.id=NEW.operational_area_id
+          AND area.information_status<>'INACTIVE'
+          AND t.is_active=true;
+
+        IF area_role IS DISTINCT FROM 'AREA'::asset_type_operational_role THEN
+          RAISE EXCEPTION USING ERRCODE='23514',
+            MESSAGE='operational area must be an active AREA asset';
+        END IF;
+
+        IF NEW.parent_id IS NULL OR NOT EXISTS (
+          WITH RECURSIVE ancestors AS (
+            SELECT id,parent_id FROM assets WHERE id=NEW.parent_id
+            UNION ALL
+            SELECT parent.id,parent.parent_id
+            FROM assets parent
+            JOIN ancestors child ON parent.id=child.parent_id
+          )
+          SELECT 1 FROM ancestors WHERE id=NEW.operational_area_id LIMIT 1
+        ) THEN
+          RAISE EXCEPTION USING ERRCODE='23514',
+            MESSAGE='operational area must be an ancestor in the physical hierarchy';
+        END IF;
+
+        RETURN NEW;
+      END $$;
+    `);
+  }
+
+  /** Restores the production F4-era paired Area+Empresa guard on rollback. */
+  private async installLegacyPairedGuard(queryRunner: QueryRunner): Promise<void> {
     await queryRunner.query(`
       CREATE OR REPLACE FUNCTION enforce_asset_operational_context()
       RETURNS trigger LANGUAGE plpgsql AS $$
@@ -59,12 +129,12 @@ export class F5OperationalContextCompatibility1790087250000 implements Migration
             MESSAGE='operator organization must be an active COMPANY-role asset';
         END IF;
 
-        SELECT r.id INTO active_relation_id
-        FROM area_company_relations r
-        WHERE r.area_id=NEW.operational_area_id
-          AND r.company_id=NEW.operator_company_id
-          AND r.relation_role='OPERATOR'::area_organization_role
-          AND r.valid_until IS NULL
+        SELECT relation.id INTO active_relation_id
+        FROM area_company_relations relation
+        WHERE relation.area_id=NEW.operational_area_id
+          AND relation.company_id=NEW.operator_company_id
+          AND relation.relation_role='OPERATOR'::area_organization_role
+          AND relation.valid_until IS NULL
         FOR KEY SHARE;
         IF active_relation_id IS NULL THEN
           RAISE EXCEPTION USING ERRCODE='23514',
@@ -75,7 +145,9 @@ export class F5OperationalContextCompatibility1790087250000 implements Migration
           WITH RECURSIVE ancestors AS (
             SELECT id,parent_id FROM assets WHERE id=NEW.parent_id
             UNION ALL
-            SELECT p.id,p.parent_id FROM assets p JOIN ancestors c ON p.id=c.parent_id
+            SELECT parent.id,parent.parent_id
+            FROM assets parent
+            JOIN ancestors child ON parent.id=child.parent_id
           )
           SELECT 1 FROM ancestors WHERE id=NEW.operational_area_id LIMIT 1
         ) THEN
@@ -86,46 +158,4 @@ export class F5OperationalContextCompatibility1790087250000 implements Migration
       END $$;
     `);
   }
-
-  private async installAreaOwnedGuard(queryRunner: QueryRunner): Promise<void> {
-    await queryRunner.query(`
-      CREATE OR REPLACE FUNCTION enforce_asset_operational_context()
-      RETURNS trigger LANGUAGE plpgsql AS $$
-      DECLARE
-        asset_role asset_type_operational_role;
-        area_role asset_type_operational_role;
-      BEGIN
-        SELECT operational_role INTO asset_role FROM asset_types WHERE id=NEW.asset_type_id;
-        IF asset_role <> 'GENERIC'::asset_type_operational_role THEN
-          IF NEW.operational_area_id IS NOT NULL OR NEW.operator_company_id IS NOT NULL THEN
-            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='Área y Empresa no reciben contexto operativo';
-          END IF;
-          RETURN NEW;
-        END IF;
-        IF NEW.operator_company_id IS NOT NULL THEN
-          IF TG_OP='INSERT' OR OLD.operator_company_id IS NULL OR NEW.operator_company_id IS DISTINCT FROM OLD.operator_company_id THEN
-            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La Empresa pertenece al contexto temporal del Área/Inspección y no al Inventario';
-          END IF;
-        END IF;
-        IF NEW.operational_area_id IS NULL THEN RETURN NEW; END IF;
-        SELECT t.operational_role INTO area_role
-        FROM assets area JOIN asset_types t ON t.id=area.asset_type_id
-        WHERE area.id=NEW.operational_area_id
-          AND area.information_status<>'INACTIVE' AND t.is_active=true;
-        IF area_role IS DISTINCT FROM 'AREA'::asset_type_operational_role THEN
-          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operational area must be an active AREA asset';
-        END IF;
-        IF NEW.parent_id IS NULL OR NOT EXISTS (
-          WITH RECURSIVE ancestors AS (
-            SELECT id,parent_id FROM assets WHERE id=NEW.parent_id
-            UNION ALL
-            SELECT p.id,p.parent_id FROM assets p JOIN ancestors c ON p.id=c.parent_id
-          ) SELECT 1 FROM ancestors WHERE id=NEW.operational_area_id LIMIT 1
-        ) THEN
-          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='operational area must be an ancestor in the physical hierarchy';
-        END IF;
-        RETURN NEW;
-      END $$;
-    `);
-  }
 }