diff --git a/apps/web/src/lib/ui/data/TaskItem.svelte b/apps/web/src/lib/ui/data/TaskItem.svelte
index 7576f1a..0f8b9ba 100644
--- a/apps/web/src/lib/ui/data/TaskItem.svelte
+++ b/apps/web/src/lib/ui/data/TaskItem.svelte
@@ -55,6 +55,7 @@
   let showAssignees = false;
   let assigneesButtonEl: HTMLButtonElement | null = null;
   $: assigneesCount = Array.isArray(assignees) ? assignees.length : 0;
+  $: canUnassign = !(groupId == null && assigneesCount === 1 && isAssigned);
   $: assigneesAria =
     assigneesCount === 0
       ? "Sin responsables"
@@ -509,9 +510,9 @@
         <button
           class="icon-btn secondary-action"
           aria-label="Soltar"
-          title="Soltar"
+          title={canUnassign ? "Soltar" : "No puedes soltar una tarea personal. Márcala como completada para eliminarla"}
           on:click|preventDefault={doUnassign}
-          disabled={busy}
+          disabled={busy || !canUnassign}
           ><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 108.01 122.88">
             <path
               class="icon-btn-svg"
diff --git a/apps/web/src/routes/api/me/tasks/+server.ts b/apps/web/src/routes/api/me/tasks/+server.ts
index 3b5bbd4..1204514 100644
--- a/apps/web/src/routes/api/me/tasks/+server.ts
+++ b/apps/web/src/routes/api/me/tasks/+server.ts
@@ -109,6 +109,10 @@ export const GET: RequestHandler = async (event) => {
 			}
 			for (const it of items) {
 				it.assignees = map.get(it.id) || [];
+				const personal = it.group_id == null;
+				const cnt = Array.isArray(it.assignees) ? it.assignees.length : 0;
+				const mine = (it.assignees || []).some((uid) => uid === userId);
+				(it as any).can_unassign = !(personal && cnt === 1 && mine);
 			}
 		}
 
@@ -209,6 +213,10 @@ export const GET: RequestHandler = async (event) => {
 		}
 		for (const it of items) {
 			it.assignees = map.get(it.id) || [];
+			const personal = it.group_id == null;
+			const cnt = Array.isArray(it.assignees) ? it.assignees.length : 0;
+			const mine = (it.assignees || []).some((uid) => uid === userId);
+			(it as any).can_unassign = !(personal && cnt === 1 && mine);
 		}
 	}
 
diff --git a/apps/web/src/routes/api/tasks/[id]/unassign/+server.ts b/apps/web/src/routes/api/tasks/[id]/unassign/+server.ts
index e4a5db0..9fab05c 100644
--- a/apps/web/src/routes/api/tasks/[id]/unassign/+server.ts
+++ b/apps/web/src/routes/api/tasks/[id]/unassign/+server.ts
@@ -54,6 +54,25 @@ export const POST: RequestHandler = async (event) => {
     }
   }
 
+  // Bloqueo de tareas personales: si es la última asignación del propio usuario, denegar
+  const stats = db
+    .prepare(`
+      SELECT COUNT(*) AS cnt,
+             SUM(CASE WHEN user_id = ? THEN 1 ELSE 0 END) AS mine
+      FROM task_assignments
+      WHERE task_id = ?
+    `)
+    .get(userId, taskId) as any;
+  const cnt = Number(stats?.cnt || 0);
+  const mine = Number(stats?.mine || 0) > 0;
+
+  if (!groupId && cnt === 1 && mine) {
+    return new Response('No puedes soltar una tarea personal. Márcala como completada para eliminarla', {
+      status: 409,
+      headers: { 'content-type': 'text/plain; charset=utf-8', 'cache-control': 'no-store' }
+    });
+  }
+
   // Eliminar asignación (idempotente)
   const delRes = db
     .prepare(`DELETE FROM task_assignments WHERE task_id = ? AND user_id = ?`)
diff --git a/src/db/migrations/index.ts b/src/db/migrations/index.ts
index 99c4ed0..45a3ac4 100644
--- a/src/db/migrations/index.ts
+++ b/src/db/migrations/index.ts
@@ -404,4 +404,37 @@ export const migrations: Migration[] = [
       } catch {}
     }
   }
+  ,
+  {
+    version: 15,
+    name: 'tasks-personal-unassign-guard',
+    checksum: 'v15-personal-unassign-2025-10-19',
+    up: (db: Database) => {
+      db.exec(`PRAGMA foreign_keys = ON;`);
+
+      // Reparar: reasignar tareas personales abiertas sin asignatarios a created_by
+      db.exec(`
+        INSERT INTO task_assignments (task_id, user_id, assigned_by, assigned_at)
+        SELECT t.id, t.created_by, t.created_by, strftime('%Y-%m-%d %H:%M:%f','now')
+        FROM tasks t
+        WHERE t.group_id IS NULL
+          AND COALESCE(t.completed,0) = 0
+          AND NOT EXISTS (SELECT 1 FROM task_assignments a WHERE a.task_id = t.id);
+      `);
+
+      // Trigger: impedir borrar el último asignatario en tareas personales
+      db.exec(`
+        CREATE TRIGGER IF NOT EXISTS trg_block_unassign_last_personal
+        BEFORE DELETE ON task_assignments
+        FOR EACH ROW
+        WHEN EXISTS (SELECT 1 FROM tasks WHERE id = OLD.task_id)
+             AND EXISTS (SELECT 1 FROM users WHERE id = OLD.user_id)
+             AND (SELECT group_id FROM tasks WHERE id = OLD.task_id) IS NULL
+             AND (SELECT COUNT(*) FROM task_assignments WHERE task_id = OLD.task_id) = 1
+        BEGIN
+          SELECT RAISE(ABORT, 'PERSONAL_UNASSIGN_FORBIDDEN');
+        END;
+      `);
+    }
+  }
 ];
diff --git a/src/services/command.ts b/src/services/command.ts
index 1cee166..5abd4a0 100644
--- a/src/services/command.ts
+++ b/src/services/command.ts
@@ -866,6 +866,13 @@ export class CommandService {
 			const res = TaskService.unassignTask(resolvedId, context.sender);
 			const due = res.task?.due_date ? ` — ${ICONS.date} ${formatDDMM(res.task?.due_date)}` : '';
 
+			if (res.status === 'forbidden_personal') {
+				return [{
+					recipient: context.sender,
+					message: 'No puedes soltar una tarea personal. Márcala como completada para eliminarla'
+				}];
+			}
+
 			if (res.status === 'not_found') {
 				return [{
 					recipient: context.sender,
diff --git a/src/tasks/service.ts b/src/tasks/service.ts
index 0aa5437..8c3cca3 100644
--- a/src/tasks/service.ts
+++ b/src/tasks/service.ts
@@ -246,7 +246,7 @@ export class TaskService {
 
     const existing = this.dbInstance
       .prepare(`
-        SELECT id, description, due_date, completed, completed_at, display_code
+        SELECT id, description, due_date, completed, completed_at, display_code, group_id
         FROM tasks
         WHERE id = ?
       `)
@@ -413,7 +413,7 @@ export class TaskService {
 
   // Soltar tarea (unassign): idempotente
   static unassignTask(taskId: number, userId: string): {
-    status: 'unassigned' | 'not_assigned' | 'not_found' | 'completed';
+    status: 'unassigned' | 'not_assigned' | 'not_found' | 'completed' | 'forbidden_personal';
     task?: { id: number; description: string; due_date: string | null; display_code: number | null };
     now_unassigned?: boolean; // true si tras soltar no quedan asignados
   } {
@@ -446,6 +446,30 @@ export class TaskService {
       };
     }
 
+    // Regla: no permitir soltar si es tarea personal y el usuario es el único asignatario
+    try {
+      const stats = this.dbInstance.prepare(`
+        SELECT COUNT(*) AS cnt,
+               SUM(CASE WHEN user_id = ? THEN 1 ELSE 0 END) AS mine
+        FROM task_assignments
+        WHERE task_id = ?
+      `).get(ensuredUser, taskId) as any;
+      const cnt = Number(stats?.cnt || 0);
+      const mine = Number(stats?.mine || 0) > 0;
+      if ((existing.group_id == null || existing.group_id === null) && cnt === 1 && mine) {
+        return {
+          status: 'forbidden_personal',
+          task: {
+            id: Number(existing.id),
+            description: String(existing.description || ''),
+            due_date: existing.due_date ? String(existing.due_date) : null,
+            display_code: existing.display_code != null ? Number(existing.display_code) : null,
+          },
+          now_unassigned: false,
+        };
+      }
+    } catch {}
+
     const deleteStmt = this.dbInstance.prepare(`
       DELETE FROM task_assignments
       WHERE task_id = ? AND user_id = ?
diff --git a/tests/unit/services/command.claim-unassign.test.ts b/tests/unit/services/command.claim-unassign.test.ts
index cbf729c..c0c2683 100644
--- a/tests/unit/services/command.claim-unassign.test.ts
+++ b/tests/unit/services/command.claim-unassign.test.ts
@@ -86,11 +86,10 @@ describe('CommandService - /t tomar y /t soltar', () => {
     expect(res[0].message).toContain('no encontrada');
   });
 
-  it('soltar: si queda sin dueño, mensaje adecuado', async () => {
+  it('soltar: personal única asignación → denegado', async () => {
     const taskId = createTask('Desc soltar', '999', '2025-09-12', ['111']);
     const res = await CommandService.handle(ctx('111', `/t soltar ${taskId}`));
-    expect(res[0].message).toContain('queda sin responsable');
-    expect(res[0].message).toContain(String(taskId));
+    expect(res[0].message).toContain('No puedes soltar una tarea personal. Márcala como completada para eliminarla');
   });
 
   it('soltar: not_assigned muestra mensaje informativo', async () => {
diff --git a/tests/unit/tasks/claim-unassign.test.ts b/tests/unit/tasks/claim-unassign.test.ts
index 3f8d85b..7ba67a4 100644
--- a/tests/unit/tasks/claim-unassign.test.ts
+++ b/tests/unit/tasks/claim-unassign.test.ts
@@ -61,18 +61,22 @@ describe('TaskService - claim/unassign', () => {
     expect(res.task?.id).toBe(taskId);
   });
 
-  it('unassign: happy path; luego not_assigned; now_unassigned=true', () => {
-    const taskId = createTask('Soltar luego de asignar', '111', '2025-09-20', ['222']);
-    // soltar por el mismo usuario
+  it('unassign: happy path con múltiples asignados; luego not_assigned; now_unassigned=false', () => {
+    const taskId = createTask('Soltar luego de asignar', '111', '2025-09-20', ['222', '333']);
     const res1 = TaskService.unassignTask(taskId, '222');
     expect(res1.status).toBe('unassigned');
     expect(res1.task?.id).toBe(taskId);
-    expect(res1.now_unassigned).toBe(true);
+    expect(res1.now_unassigned).toBe(false);
 
-    // idempotente si no estaba asignado
     const res2 = TaskService.unassignTask(taskId, '222');
     expect(res2.status).toBe('not_assigned');
-    expect(res2.now_unassigned).toBe(true);
+    expect(res2.now_unassigned).toBe(false);
+  });
+
+  it('unassign: personal + único asignado → forbidden_personal', () => {
+    const taskId = createTask('Personal única asignación', '111', '2025-09-21', ['222']);
+    const res = TaskService.unassignTask(taskId, '222');
+    expect(res.status).toBe('forbidden_personal');
   });
 
   it('unassign: not_found', () => {