Shopify SMS and WhatsApp Notifications App for Indian Stores

The free Fast2SMS app for Shopify sends order updates, COD alerts, abandoned checkout reminders and OTP login codes to your customers on SMS and WhatsApp, straight from your store. You install it from the Shopify App Store, paste your Fast2SMS API key, switch on the events you want and pay only per message from your own Fast2SMS wallet. There is no monthly fee, no trial that runs out and no developer needed.

This guide is written for Indian Shopify store owners. It covers every screen of the setup with real screenshots, the DLT and WhatsApp template rules you must follow in India, what each message costs, message examples you can copy, and fixes for the problems store owners ask us about most.

What the Fast2SMS Shopify app does

Shopify gives you a great storefront, but Indian shoppers live on their phones. They want an order confirmation the moment they pay, a message when the parcel ships and a heads-up before the delivery rider arrives. Email alone does not do that job in India. The Fast2SMS app connects your store to the bulk SMS and WhatsApp Business API services of your Fast2SMS account, so these messages go out on their own.

In one app you get:

• OTP login for your storefront. Customers sign in with their mobile number and a one time password instead of a password they keep forgetting. The code can go on SMS or WhatsApp, with automatic fallback to the other channel.
• Automatic order notifications. Twelve order and customer events, including order placed, payment, fulfillment, out for delivery, delivered, refunds, COD orders, abandoned checkout and a welcome message. For each event you choose SMS, WhatsApp or both.
• Invoice PDF on WhatsApp. The app generates an invoice for every order and can attach it to your WhatsApp message.
• COD alerts. A separate event fires only for Cash on Delivery orders, and copies can reach up to 10 team numbers instantly, so you can check doubtful orders before shipping.
• Abandoned checkout reminders. A reminder with the cart link after a delay you set, cancelled automatically if the customer completes the order in the meantime.
• Manual and bulk messages. Send a message to a single customer from the Customers page, or message many customers at once, using your approved templates.
• Logs. Every OTP and alert is recorded with its delivery status, and failed messages can be retried with one click.

The app is built by Fast2SMS itself, not by a third party reselling message routes. Messages go through your own Fast2SMS account, which is why the app has no platform markup and why full delivery reports stay in your own panel. You can see the whole list of free plugins on the Fast2SMS integrations page.

What you need before you start

Setup takes about fifteen minutes once these are ready:

• A Shopify store with Indian (+91) customers.
• A free Fast2SMS account. Signup at fast2sms.com. New accounts get ₹50 free credit, enough to test the whole setup.
• Your API key. It is in the Dev API section of the Fast2SMS panel. One key works for every integration and for the REST API.
• For SMS: approved DLT templates. Indian rules need every business SMS to match a DLT-approved template. Fast2SMS gives free DLT support for entity, sender ID and template approval.
• For WhatsApp: a connected WhatsApp Business number with approved templates. Connecting a number is free with no monthly or setup fee, and you can keep using your existing WhatsApp Business app number.
• For OTP login: an OTP ID created in the Smart OTP section of your Fast2SMS panel. We cover this in Step 2.

You do not need SMS and WhatsApp both on day one. WhatsApp templates need Meta approval but no DLT registration, so you can start with WhatsApp order updates and add SMS once your DLT templates are approved.

Step 1: Install the app and connect your API key

1. Open the app listing. Go to apps.shopify.com/fast2sms while logged in to your Shopify admin and click install. The app itself is free; you pay only per message.
2. Approve the permissions. Shopify asks you to choose the store (if you run more than one) and to allow the app to access your store data so it can send messages.
3. Open the Setup tab. Once installed, open Fast2SMS from the Apps section of your Shopify admin.
4. Paste your API key and click Validate & Save. The key is checked live against your Fast2SMS account and stored encrypted. After this, everything else in the app is switches and dropdowns.

Step 2: Set up OTP login on your storefront

OTP login lets customers sign in with their 10-digit mobile number and a code, with no password to remember and no reset emails for your support team.

1. Create an OTP ID in Fast2SMS. In your Fast2SMS panel, open the Smart OTP section and add an OTP template. Choose the primary channel, SMS or WhatsApp, and optionally a fallback on the other channel. This one setting decides how your Shopify OTPs are delivered. The Smart OTP walkthrough shows every screen.
2. Enable OTP login in the app. Open the OTP Login tab in the Shopify app, switch on Enable OTP login and paste your OTP ID.
3. Add the widget to your theme. Copy the one-line snippet shown in the app. In Shopify go to Online Store → Themes → Edit code, open theme.liquid and paste the line just before the closing </body> tag. This is copy and paste, not coding.
4. Save and test. Open your store’s login page in a private window. You should now see Login with OTP.

What your customer sees

On the login page the customer types their mobile number and taps Send OTP. The code arrives on SMS or WhatsApp, whichever your OTP ID is set to. If the first channel fails, the same code goes out on the second channel automatically, so nobody is left waiting. They type the code and they are logged in. On WhatsApp, authentication templates show your verified business name and a Copy code button, which makes the code easy to enter.

Fast2SMS generates, sends, expires and checks every code on its servers, and a customer can request a resend within a 10 minute window. Your store never stores OTPs. If you run a custom storefront or app outside Shopify, the same OTP ID works with the OTP SMS API; see the WhatsApp OTP API guide for the details.

Step 3: Turn on order notifications (SMS and WhatsApp)

OTP login is optional. Order notifications are where most stores see value first, and they work whether or not you use OTP login. Open the Automations tab:

For each event you switch on:

1. Pick the channel: SMS, WhatsApp or both.
2. Click Fetch from Fast2SMS to load your approved templates from your account.
3. Map each variable to Shopify order data with a dropdown, for example customer name, order number or amount.
4. Check the live phone preview to see exactly what the customer will receive.
5. Send a test to your own number, then save.

Which event should send what

The app has twelve events. This table covers the ones most Indian stores switch on first and the job each message does.

Invoice PDF on WhatsApp

The app auto-generates a professional invoice for every order. When you map variables for a WhatsApp template that has a document header, type {invoice_url} and the order’s invoice PDF attaches itself. Customers keep the invoice in their chat, and your team stops answering “please send my bill” messages. The invoice PDF guide has the details.

For ready wording for each event, see 12 Shopify order events: what to send at each step and the Shopify WhatsApp order notifications guide.

COD alerts, admin numbers and lower RTO

Cash on Delivery is still how a large share of Indian shoppers pay, and it is where stores lose the most money. A fake number or a customer who forgot they ordered means a parcel that comes back, and you pay shipping both ways. The app gives COD orders their own event, so you can send a COD-specific message that asks the customer to keep cash ready and confirms the order is genuine.

In Settings you can add up to 10 admin numbers. Any automation with Also alert admin switched on sends a copy to all of them, so your team hears about every new order and every COD order the moment it happens. Your packing team can then call doubtful COD orders before the parcel leaves.

Two more habits help: verify numbers at the start with OTP login, so accounts carry working numbers, and send the out-for-delivery message so the customer expects the rider. Read how Shopify stores cut COD RTO and Shopify COD verification methods compared for more ideas.

Abandoned checkout recovery on WhatsApp

Many shoppers reach checkout, get distracted and leave. If they entered a mobile number, the abandoned checkout event can send them a reminder with a link straight back to their cart. You set the delay in Settings. If the customer completes the order before the reminder is due, the reminder is cancelled automatically, so nobody gets a “you forgot something” message after paying.

The same Settings page holds a marketing consent option and a data retention setting next to the abandoned checkout delay. Keep the reminder short, mention the product, and include the cart link. Do not send several reminders for the same cart; one well-timed message works better than three. The full walkthrough is in the Shopify abandoned cart WhatsApp guide.

Logs, opt-outs and settings

The Logs tab records every OTP and alert with the time, event, channel, masked mobile number and delivery status. Failed messages show the reason and can be retried with one click. Because messages go through your own Fast2SMS account, full delivery reports also stay in your Fast2SMS panel, and can also be pushed to your own server through webhooks.

The opt-out list in Settings matters for trust and for compliance. Numbers on it never receive marketing messages from the app. When a customer asks you to stop promotional messages, add their number here.

Manual messages and custom workflows

Besides automatic events, the app lets you message customers by hand and build your own automations with Shopify’s workflow tools. The screenshots in this section come from the Fast2SMS for Shopify integration guide. Your screens may look a little different after app updates, but the steps are the same in spirit.

Install screens and authorisation

When you install, Shopify first asks which store to connect, then asks you to allow the app to access your store data. The guide then shows signing in to Fast2SMS (with email or Google), authorising your Shopify domain and connecting Fast2SMS with your domain and API key.

Send a message to one customer

1. In Shopify admin, open Customers and click the customer you want to message.
2. Click More actions and choose Send Fast2SMS SMS & WhatsApp Message.
3. Select your Sender ID and route. The customer’s phone and mobile fields are fetched automatically; pick the number to use. Enter a default country code for numbers saved without one.
4. Click Templates to see your approved templates and choose one. Only approved templates can be sent on the DLT route.
5. Check the preview, click # to fill placeholder values for a personal message, then click Send. A pop-up confirms the message was sent.

To message many customers at once, the app supports bulk messages to Shopify customers, and you can also run bigger campaigns from the Fast2SMS panel with Excel upload and scheduling. See bulk SMS and WhatsApp campaigns for Shopify customers and our bulk WhatsApp message guide.

Build a custom automation with a workflow code

If you need a trigger that the built-in events do not cover, the app can give you a workflow code to use in a Shopify automation:

1. Open a customer, open the Fast2SMS app, pick the sender, route and template, fill the placeholders and click Get Workflow code. You get a Webhook URL and a workflow code.
2. In Shopify go to Marketing → Automations → Create Automation. Choose a template or a custom automation and set the trigger.
3. Click + to add an action and choose Send HTTP request. Paste the Webhook URL into the URL field and set the method and header as the help guide shows.
4. Paste the workflow code into the Body. Replace the value of the “number” or “to” parameter with the customer’s phone field (Add a variable → Customers → phone), and the “record Id” value with the customer Id. Fill any template variables the same way.
5. Set the default_country_code value for numbers saved without a country code, then click Turn on workflow.

DLT and WhatsApp templates for Shopify stores

Every message the app sends uses an approved template. The rules differ by channel, and getting this right is the single biggest reason setups go smoothly or get stuck.

SMS: DLT registration

In India, TRAI rules require every business sending SMS to register on a DLT portal. You register your business as an entity, get a sender ID (the 6-character header customers see) approved, and get each message template approved. A Shopify SMS that does not match an approved template will not be delivered. Fast2SMS helps you with all three steps for free; start on the DLT registration page.

Newer DLT rules use typed variable tags with length limits. The ones Shopify stores use most:

Copy-paste examples are in Shopify DLT SMS templates, and common questions are answered in Shopify SMS alerts with DLT.

WhatsApp: Meta template approval

WhatsApp does not use DLT. Instead, each template is approved by Meta in one of the categories: utility (order and delivery updates), authentication (OTPs), or marketing (offers and campaigns). Meta decides the final category when it approves the template, and the category sets the price. Fast2SMS reviews your templates before you submit them to Meta, which helps avoid rejections. Ready wording is in Shopify WhatsApp message templates.

Message examples that work

Good store messages are short, name the order, and tell the customer what happens next. Here are examples you can adapt. On SMS the variables become DLT tags; on WhatsApp they become template variables mapped in the app.

A WhatsApp order confirmation can carry more: the order summary, the invoice PDF and a button to your store. Keep it under five short lines so it reads well on a phone.

Five habits of good store messages

• Brand name in every message. Customers should never wonder who is texting them.
• One purpose per message. A delivery update should not also sell a new collection.
• Time campaigns well. Order updates go out when the event happens; schedule offers and campaigns for daytime hours.
• Use the customer’s language. Unicode SMS in Hindi and other Indian languages is supported, but note that one Unicode SMS holds 70 characters instead of 160.
• Respect opt-outs. Add anyone who asks to stop to the opt-out list straight away.

What it costs

The Fast2SMS Shopify app is free to install and use. There is no monthly fee, no setup fee and no trial that expires. You pay only for messages, from the prepaid wallet in your Fast2SMS account. New accounts get ₹50 free credit, and you can recharge from ₹100 whenever you need.

WhatsApp rates (India)

WhatsApp is billed on delivery. If a message fails, for example because the number is not on WhatsApp, the amount is refunded to your wallet automatically within 48 hours. High-volume plans go down to ₹0.11 per message; talk to sales for those. Full details are on the WhatsApp pricing page.

SMS rates

SMS uses one per-SMS rate for all DLT SMS, including OTP and transactional, and the rate falls as your recharge grows:

Validity applies only to the discounted rate, never to your money: the wallet balance does not expire. 18% GST is added on the recharge amount and a GST invoice is generated for every payment. A standard SMS is 160 characters; longer messages count as more than one SMS. See the bulk SMS pricing page for the live slabs.

A quick monthly estimate

Say your store ships 1,000 orders a month and sends three WhatsApp utility updates per order (confirmation, shipped, delivered). That is 3,000 messages at ₹0.25, or ₹750 a month plus GST, and failed messages are refunded. Add OTP logins at the same ₹0.25 rate on WhatsApp, or at your SMS slab rate. Your exact bill depends on the events you switch on, so start with the essentials and add more once you see the results. For a deeper breakdown, read Shopify SMS and WhatsApp cost.

How to compare Shopify SMS and WhatsApp apps

There are many messaging apps in the Shopify App Store, and some are built for other countries. Instead of comparing logos, ask every app the same questions. This table shows the questions and how the Fast2SMS app answers them.

Also see best SMS and WhatsApp apps for Shopify India and, if you are still choosing a platform, Shopify vs WooCommerce. Running WooCommerce instead? Read our WooCommerce SMS and WhatsApp plugin guide.

Troubleshooting

The API key does not validate

Copy the key again from the Dev API section, making sure no space is added at the start or end. If you regenerated the key in the panel, paste the newest one.

Fetch from Fast2SMS shows no templates

Templates appear only after they are approved: DLT templates added to your Fast2SMS account for SMS, and Meta-approved templates for WhatsApp. Also check that the API key belongs to the same account that holds those templates.

Login with OTP does not appear on the store

Check three things: your store uses legacy customer accounts, Enable OTP login is switched on with a valid OTP ID, and the widget line is saved in theme.liquid of the theme that is actually published. If you changed themes, paste the snippet into the new theme too.

Customers say the OTP is not arriving

Open the Logs tab to see the status and reason. Add a fallback channel to your OTP ID so a code that fails on one channel goes out on the other. For SMS, make sure your DLT OTP template is approved and your wallet has balance. The Smart OTP guide explains why codes go missing and how fallback fixes it.

WhatsApp messages fail for some customers

Usually the number is not on WhatsApp or was saved without the right country code. Set the default country code, send SMS as well for critical updates, and remember that failed WhatsApp messages are refunded automatically.

SMS is rejected

The text sent must match the approved DLT template exactly, with variables in the right places and within their length limits. A mapped variable that is longer than its tag allows, such as a long URL in an alphanumeric tag, can cause rejection.

Still stuck? Write to [email protected], call +91-6262778822, use the contact page, or book a free meeting with the team. All support is free.

Why Indian Shopify stores choose Fast2SMS

• Since 2011. Fast2SMS has run business messaging in India for more than 15 years, on infrastructure with 99.9% uptime.
• One account, every channel. SMS, WhatsApp, RCS and OTP from the same wallet and API key, with the same key working in Shopify, WooCommerce and your own code through the REST API.
• Free extras with WhatsApp. A WhatsApp Live Chat team inbox and a drag-and-drop chatbot builder come free with every account, so customers who reply to an order update can be answered quickly. Learn more in the official WhatsApp Business API guide.
• Free DLT help for entity, sender ID and template approval.
• Pay per message only, with delivery-basis billing and automatic refunds on failed WhatsApp messages.

If you want to see it working before you commit, signup at fast2sms.com, use the ₹50 free credit, install the app and send test messages to your own phone. Setup takes about fifteen minutes. There is also a 100+ question FAQ on the Shopify app and a Hindi FAQ, plus the complete Fast2SMS Shopify app guide and the OTP integration walkthrough.