How to build a WhatsApp opt-in list legally: QR codes, website, ads and checkout

Before you start

To build a WhatsApp opt-in list, you need two things for every person on it: their phone number and a record that they agreed to receive messages from your business on WhatsApp. This guide shows how to ask at each place customers meet you, what to write, and how to store the answer so you can prove it later. It complements our article on WhatsApp opt-in best practices, which explains the policy, by turning it into a setup you can finish in an afternoon.

Two sets of rules apply in India:

• WhatsApp's Business Messaging Policy says you may contact people only if you have their number and their opt-in, that the opt-in must clearly state they are agreeing to receive messages from your named business, and that you must honour requests to stop.
• The Digital Personal Data Protection Act, 2023 (section 6) describes valid consent as free, specific, informed, unconditional and unambiguous with a clear affirmative action, limited to the stated purpose, and lets people withdraw it as easily as they gave it.

Step 1: write the consent wording

Good opt-in wording answers four questions in one or two lines: who is messaging (your business name as customers know it), what you will send, how often, and how to stop. Ask separately for marketing; order and appointment updates are a different purpose.

Avoid vague wording such as I agree to be contacted or by continuing you accept communications. They do not name WhatsApp, do not name the purpose and are not a clear action.

Step 2: set up how you will record consent

A list is only as good as its records. For every opt-in, keep the date and time, the source (QR, website, ad, checkout, form), and the wording shown. In Broadchat:

1. Create a tag such as wa-marketing-yes under CRM → Tags.
2. Create two custom fields under CRM → Super Field: optin_date and optin_source.
3. When you import an existing list through CRM → Imports, include columns for the source and date, and import only people for whom you have a record. Old customer numbers with no consent record stay out of marketing sends.
4. On each contact in CRM → Contact, the Subscribed to broadcasts setting controls whether a campaign sent to all contacts includes them. Untick it for anyone who opts out.

Build your marketing segment in CRM → Segment from the tag, not from the whole contact book.

Step 3: add a QR code in your store

A QR code at the counter, on packaging or on a bill turns an in-person visit into a WhatsApp chat. Make the code open a chat with a pre-filled message such as Hi, I'd like updates from Sunrise Clinic, so the customer only taps send.

• In Broadchat, open Channels → All Channels, open your number and use the QR Codes tab to create a code with its QR Code Message. Use one code per placement so you can see which one works.
• Without a platform, create a link with the WhatsApp link generator and print it with the WhatsApp QR code generator.

The scan starts a chat; it does not prove the person wants promotions. Reply with the opt-in question from step 1, and tag only those who answer YES. A chatbot with a Match Keyword trigger in Chatbots → Chatbots can do this automatically: on YES it tags the contact and uses a Save Variable Value step to store the date and source in your Super Fields.

Step 4: add WhatsApp to your website

Website visitors who have a question are easy to convert into chats. Two options:

• A chat widget. In Broadchat, Chat Widget → Widget adds a chat widget to your website; visitor chats land in the same inbox as WhatsApp, and the widget records its leads.
• A click-to-chat link on product, contact and order-tracking pages, built with the link generator.

As in the store, ask the opt-in question once the chat starts. If you also collect numbers in a website form, the form needs its own WhatsApp checkbox (step 6).

Step 5: ask leads from Click-to-WhatsApp ads

A Click-to-WhatsApp ad is one of the fastest ways to start conversations with new people, and messages in the free entry point window cost nothing for up to 7 days when you reply within 24 hours. But the ad chat is not marketing consent. Answer the person's question first, then ask whether they want future offers. Our guide to setting up Click-to-WhatsApp ads shows how to send the question automatically from a chatbot.

Step 6: add an unticked box at checkout and in forms

Checkout is where you collect the most numbers, and where consent is most often faked by accident. Rules of thumb:

• The WhatsApp marketing box is separate from the terms-and-conditions box and unticked by default.
• Buying must not depend on ticking it.
• Store the box value and the timestamp with the order, and pass them into your contact list with the source checkout.
• Order updates (confirmation, dispatch, delivery) can be a separate box or part of the order flow; keep them apart from offers.

For forms inside WhatsApp, a WhatsApp Flow built in WhatsApp Mini-Apps → Mini Apps can include a consent checkbox, and the chatbot's Mini-App Submission trigger can tag the contact when it is ticked.

Step 7: confirm, then honour opt-outs

Send each new subscriber a short confirmation so they know what they signed up for:

Then make leaving easy. Add a quick-reply button such as Stop offers to marketing templates. After each campaign, open the campaign report in CRM → Bulk Campaign and filter Reply is → Stop Notification to find people who replied STOP, then remove their tag and untick Subscribed to broadcasts. Stopping marketing must not stop the order updates the customer still needs.

After launch: keep the list healthy

• Re-confirm old opt-ins that are more than a year old or came from a source you cannot document.
• Watch your quality rating. Blocks and reports from people who do not remember subscribing lower it; see quality rating and messaging limits.
• Send what you promised. If the wording said twice a month, do not send daily.

A clean opt-in list is the base of every other WhatsApp marketing play, from festive campaigns to re-engagement; see the full WhatsApp marketing strategy. Agencies that run lists for many clients can offer the same setup under their own brand through the partner program.