WhatsApp’s 24-hour window, explained for shop owners

If you have started using WhatsApp for your shop through the Business Platform (the "API" version, not only the app on your phone), you have probably heard people mention "the 24-hour window". It sounds technical, but the idea is simple, and once it clicks, a lot of WhatsApp's rules start to make sense.

This post explains what the window is, why order updates need approved templates, and what happens when a customer has gone quiet for more than a day.

The short version

When a customer sends your business a message, a 24-hour window opens. Inside that window, you can reply however you like: plain text, photos, a product card, a payment link, a voice note. Every new message from the customer starts the 24 hours again.

Once 24 hours pass without a message from the customer, the window closes. From then on, you can only start a conversation using a template — a message whose wording WhatsApp has reviewed and approved in advance.

That is the whole rule. Everything else follows from it.

Why WhatsApp works this way

WhatsApp wants people to feel safe giving their number to a business. If any business could send any message at any time, inboxes would fill up with offers nobody asked for, and people would stop trusting business chats.

So the line is drawn around who spoke last. If the customer has just written to you, they are clearly expecting a reply, and you can talk freely. If they have not written in a while, you may still need to reach them — to say their parcel has shipped, for example — but it has to be a message of an approved kind, in approved wording.

It is a fair trade. Customers get a calm inbox, and shops still get a reliable way to send the updates that matter.

Free-form messages: inside the window

Most of a normal sales chat happens inside the window. A customer asks, "Is the blue kurta available in M?" You reply. They ask about delivery to Indore. You reply. They say, "Ok send link." You send the payment link.

All of that is free-form. There is no template to fill and no approval to wait for. This is also where a WhatsApp agent does most of its work: answering questions, suggesting products, building the cart and sending the link while the customer is still in the chat.

A practical tip: if a customer is in the middle of deciding, reply quickly. A reply within minutes keeps the conversation — and the window — alive. A reply the next evening may arrive after the window has closed, and then you need a template just to say hello again.

Templates: outside the window

A template is a message you write once, submit to WhatsApp for review, and then reuse. It can have blanks that are filled in each time, such as the customer's name or order number. For example:

Hi Priya, your order #1042 has been packed and will be shipped today. We will send tracking details once it is on the way.

WhatsApp groups templates by purpose. The one that matters most for a shop is utility: messages about something the customer has already started, like an order confirmation, a payment receipt, a shipping update or a return update. There are also marketing templates, for offers and announcements, which are treated more strictly and are usually priced differently.

Why order updates need approved templates

Think about the life of a typical order. The customer pays on Monday evening. You pack it on Wednesday. The courier picks it up on Thursday. It is delivered on Saturday.

By Wednesday, the customer has probably not messaged you since Monday, so the window is closed. If you want to tell them "Your order is packed", that message has to be an approved utility template. The same goes for "Shipped", "Out for delivery" and "Your refund has been processed".

This is why it is worth setting up a small set of templates before you go live: order confirmation, payment link, payment received, order status update, return update. Approval takes a little time, so do it early. Once they are approved, the updates can go out on their own at the right moments without you thinking about the window at all.

Keep templates plain and specific. "Your order #1042 has shipped" is easy to approve and easy for the customer to understand. A template that slips a discount offer into a shipping update may be treated as marketing instead.

What happens after 24 hours

When the window has closed and the customer has not replied, you have three sensible options.

Send a template. If there is a real reason to reach them — their order moved forward, a return was approved — a utility template is the right tool.

Wait for them. If there is nothing new to say, waiting is often best. The moment they message again, the window reopens and you can reply freely.

Use another channel. Some updates matter enough that you do not want them to depend on WhatsApp alone. If a template cannot be sent for some reason, a short SMS or an email with the same update makes sure the customer still hears from you.

Resandhi handles this for you. Inside the window, the agent replies normally. Outside it, order updates go out as your approved templates, and if WhatsApp is not an option, the same update can go by SMS or email instead. You do not need to track the clock for each customer.

A few common questions

Does the window reset if I send a message? No. Only a message from the customer opens or renews it.

Can I reply to a customer who wrote to me yesterday afternoon? Only if it is still within 24 hours of their last message. After that, you need a template.

Does this apply to the WhatsApp Business app on my phone? The 24-hour window is a rule of the WhatsApp Business Platform, which is what tools like Resandhi use to reply for you. If you only ever reply by hand from the app, WhatsApp's own help pages are the best guide.

In one line

Talk freely while the customer is talking to you; use approved templates for updates after that; and keep SMS or email as a backup for the updates that must arrive.

If you would like updates like these to go out on their own, you can try Resandhi free for 7 days on your own catalogue.