What is WhatsApp's 24-hour window?

The rule, in one sentence

You can reply freely, but you can't start freely.

Every message a customer sends you opens or resets a 24-hour window. Inside that window you send text, images, voice notes, whatever you want, with nobody's approval. Once the window closes — or when you want to write first — WhatsApp only lets you send a template approved by Meta.

Why it exists

So the platform doesn't fill with messages nobody asked for. It is the reason WhatsApp still has extraordinary read rates, and it is also why no provider can skip it, whatever they charge. If someone offers you "message anyone whenever you want", they're either selling you templates without saying so, or they're going to get your number banned.

What confuses people most

• The CUSTOMER opens the window, not you. Replying doesn't extend it: only their next message resets it.
• It's per contact, not per number: you have a separate window open with each person.
• A template does not open a window by itself. It opens the conversation; the free-reply window opens when the person answers.
• There's a more generous, free window when the conversation starts from a click-to-WhatsApp ad: it can last up to 7 days and, while it is open, Meta doesn't charge for messages.

⚠ What Meta charges since 1 October 2026

Service is the free-form text you reply within 24 hours of your customer's last message. Since 1 October 2026 Meta charges it per delivered message (in its rate card, the same figure as each country's utility rate), and also utility sent while the window is open. The first 1,000 service messages per number per month are free; after that Meta charges for each reply and needs your card added in Meta. Meta charges this, not WAIA Connect: your trial is still free. The 24-hour window still exists and defines whether you can send free-form text.

What you were actually charged is in your Meta billing. While a number is within its 1,000 free, Meta marks each reply free_customer_service and billable: false; from the month's 1,001st, regular and billable: true. Meta's month resets at midnight in your Meta account's time zone, and what you don't use doesn't roll over.

Click-to-WhatsApp ads: when the conversation starts from one of those ads, a window opens that can last up to 7 days; while it is open Meta doesn't charge for messages.

Checked against Meta's documentation on 2026-10-23.

How to live with it in practice

• If your case is replying (support, enquiries, inbound sales), you live inside the window and may never need a template.
• If you need to notify something (an appointment, a shipment, an invoice), prepare the template before you need it. Meta usually reviews them in minutes, but approval is Meta's call and you won't get it at 3am on the day you need it.
• Store the timestamp of each contact's last message. It's one field in your database and it avoids 90% of rejections: if more than 24 hours have passed, send a template instead of attempting free text.

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