Appbrew x TrustSignal OTP Sign-In

Last updated: July 20, 2026

Secure, password-free login over SMS and email

1. What is it?

TrustSignal is the built-in SMS and email provider that powers one-time-password (OTP) sign-in in your app. Instead of remembering a password, customers log in or create an account by entering a one-time code sent to their phone or email — a faster, more secure experience that reduces friction at sign-up and checkout.

It's the default provider for OTP Sign-in and works for both Indian and international customers. Key benefits:

  • Fast, secure login with a one-time code — no passwords to manage

  • Works over both SMS and email.

  • Supports international phone numbers with their own templates and sender IDs

2. Which plans is it available on?

TrustSignal OTP Sign-In is available on the Pro and Enterprise plans.

3. What's needed to enable it?

Everything is configured from the OTP Sign-in integration in your Appbrew dashboard. You'll need a TrustSignal account and your approved templates ready before you start.

  1. In your dashboard, go to Integrations and select OTP Sign-in.

Where: Appbrew dashboard › Integrations › OTP Sign-in.

  1. Under Phone Provider, choose TrustSignal (it's selected by default), then enter your API Key, Sender ID, Message Template (include {otp} where the code should appear), and Template ID.

  2. (Optional) For customers outside India, add an International Sender ID and an International Message template.

  3. (Optional) To also send OTPs by email, choose TrustSignal under Email Provider and enter your Email API Key, From Email Address, Email Subject, and Email Template ID.

  4. Save your settings. OTP login goes live right away.

For SMS delivery in India, you'll also need a DLT-registered account and an approved template. If you don't have one yet, TrustSignal can guide you through registration. You don't need to send any keys or credentials to Appbrew — everything is entered directly in your own dashboard.

4. FAQ

What do I need to get started?

A TrustSignal account plus your API Key, Sender ID, an approved message template with a dynamic OTP variable (e.g. {otp}), and the Template ID. If you're using email OTP, you'll also need your sender email address and email template details.

Does this work for international phone numbers?

Yes. TrustSignal supports international SMS, and you can set a separate message template and sender ID for international delivery in the dashboard.

What happens if an SMS doesn't go through?

If you've configured both SMS and email with TrustSignal, the system automatically falls back to email so your customer still receives their code.

My customers aren't receiving OTPs — what should I check?

Confirm the API Key, Sender ID, and Template ID are entered correctly, and that the customer's phone number is in the right format including the country code.

Is DLT registration required?

Yes, for SMS delivery in India. If you don't have a DLT account, TrustSignal can guide you through setup — it typically requires your business details and a one-time fee paid directly to the DLT portal.

Do I need developer help to enable this?

No. Everything is configured from your dashboard. If you need help getting your TrustSignal account or templates approved, Appbrew's support team can connect you with a TrustSignal contact.