diff --git a/src/services/command.ts b/src/services/command.ts
index 31fe1a9..d5228a5 100644
--- a/src/services/command.ts
+++ b/src/services/command.ts
@@ -1025,13 +1025,20 @@ export class CommandService {
 			const n = parseInt(raw || '8', 10);
 			return Number.isFinite(n) && n > 0 ? n : 8;
 		})();
+		const MAX_FALLBACK_DIGITS = (() => {
+			const raw = (process.env.ONBOARDING_FALLBACK_MAX_DIGITS || '').trim();
+			const n = parseInt(raw || '15', 10);
+			return Number.isFinite(n) && n > 0 ? n : 15;
+		})();
 
-		type FailReason = 'non_numeric' | 'too_short' | 'invalid';
+		type FailReason = 'non_numeric' | 'too_short' | 'too_long' | 'from_lid' | 'invalid';
 		const isDigits = (s: string) => /^\d+$/.test(s);
-		const plausibility = (s: string): { ok: boolean; reason?: FailReason } => {
+		const plausibility = (s: string, opts?: { fromLid?: boolean }): { ok: boolean; reason?: FailReason } => {
 			if (!s) return { ok: false, reason: 'invalid' };
+			if (opts?.fromLid) return { ok: false, reason: 'from_lid' };
 			if (!isDigits(s)) return { ok: false, reason: 'non_numeric' };
 			if (s.length < MIN_FALLBACK_DIGITS) return { ok: false, reason: 'too_short' };
+			if (s.length >= MAX_FALLBACK_DIGITS) return { ok: false, reason: 'too_long' };
 			return { ok: true };
 		};
 		const incOnboardingFailure = (source: 'mentions' | 'tokens', reason: FailReason) => {
@@ -1056,7 +1063,10 @@ export class CommandService {
 				}
 				const resolved = IdentityService.resolveAliasOrNull(norm);
 				if (resolved) return resolved;
-				const p = plausibility(norm);
+				// detectar si la mención proviene de un JID @lid (no plausible aunque sea numérico)
+				const dom = String(j || '').split('@')[1]?.toLowerCase() || '';
+				const fromLid = dom.includes('lid');
+				const p = plausibility(norm, { fromLid });
 				if (p.ok) return norm;
 				// conservar para copy JIT
 				unresolvedAssigneeDisplays.push(norm);
@@ -1080,7 +1090,7 @@ export class CommandService {
 				}
 				const resolved = IdentityService.resolveAliasOrNull(norm);
 				if (resolved) return resolved;
-				const p = plausibility(norm);
+				const p = plausibility(norm, { fromLid: false });
 				if (p.ok) return norm;
 				// conservar para copy JIT (preferimos el token limpio v)
 				unresolvedAssigneeDisplays.push(v);
diff --git a/tests/unit/services/command.onboarding-jit-lid.test.ts b/tests/unit/services/command.onboarding-jit-lid.test.ts
new file mode 100644
index 0000000..e69a729
--- /dev/null
+++ b/tests/unit/services/command.onboarding-jit-lid.test.ts
@@ -0,0 +1,61 @@
+import { describe, it, expect, beforeAll, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../../src/db';
+import { CommandService } from '../../../src/services/command';
+import { ResponseQueue } from '../../../src/services/response-queue';
+import { TaskService } from '../../../src/tasks/service';
+
+describe('CommandService - JIT onboarding para menciones @lid y números demasiado largos', () => {
+  let memdb: Database;
+
+  beforeAll(() => {
+    memdb = new Database(':memory:');
+    initializeDatabase(memdb);
+    (CommandService as any).dbInstance = memdb;
+    (TaskService as any).dbInstance = memdb;
+    (ResponseQueue as any).dbInstance = memdb;
+  });
+
+  beforeEach(() => {
+    process.env.NODE_ENV = 'test';
+    process.env.ONBOARDING_ENABLE_IN_TEST = 'true';
+    process.env.CHATBOT_PHONE_NUMBER = '34600000000';
+    memdb.exec('DELETE FROM response_queue');
+    memdb.exec('DELETE FROM users');
+    memdb.exec('DELETE FROM tasks');
+    memdb.exec('DELETE FROM task_assignments');
+  });
+
+  it('cuando la mención proviene de @lid, no se asigna y se devuelve un DM JIT al creador con wa.me', async () => {
+    const res = await CommandService.handle({
+      sender: '34611111111',
+      groupId: '123@g.us',
+      message: '/t n Pedir cita @166348562894911',
+      mentions: ['166348562894911@lid']
+    });
+
+    const toCreator = res.filter(r => r.recipient === '34611111111').map(r => r.message).join('\n');
+    expect(toCreator).toMatch(/activar/i);
+    expect(toCreator).toMatch(/https:\/\/wa\.me\/34600000000/);
+
+    // No se devuelve ningún mensaje dirigido al "número" opaco
+    const recipients = res.map(r => r.recipient);
+    expect(recipients).not.toContain('166348562894911');
+  });
+
+  it('cuando el token @ lleva 15+ dígitos, no es plausible y devuelve DM JIT al creador', async () => {
+    const res = await CommandService.handle({
+      sender: '34622222222',
+      groupId: '123@g.us',
+      message: '/t n Tarea prueba @123456789012345',
+      mentions: []
+    });
+
+    const toCreator = res.filter(r => r.recipient === '34622222222').map(r => r.message).join('\n');
+    expect(toCreator).toMatch(/activar/i);
+    expect(toCreator).toMatch(/https:\/\/wa\.me\/34600000000/);
+
+    const recipients = res.map(r => r.recipient);
+    expect(recipients).not.toContain('123456789012345');
+  });
+});