Quick answer
The WhatsApp 24-hour customer service window is the period after a customer's last message during which a business can reply with any free-form message, including text, photos, documents and buttons. Each new customer message restarts the 24 hours. Once the window closes, the business can only contact that customer with a pre-approved template message, which is usually charged at a higher rate.
Key takeaways
- The window opens when a customer messages you and restarts with every new message they send.
- Inside the window you can send any message type: text, media, voice notes, locations, buttons and lists.
- After 24 hours of silence from the customer, you can only send approved template messages.
- Replies inside the window cost less than templates, so answering promptly saves money.
- The rule applies to the WhatsApp Business API; the free WhatsApp Business app does not use it.
The WhatsApp 24-hour customer service window is the period that starts when a customer sends your business a message and lasts 24 hours from their most recent message. Inside it you can reply however you like; outside it you need an approved template.
This explainer is for business owners, support leads and agents on the WhatsApp Business API. It covers how the window works, what you can send inside and outside it, how it affects your bill, and how to stop it catching your team out.
What is the WhatsApp 24-hour window?
It is a rolling 24-hour period, measured from the customer's last message to you, during which your business may send non-template messages. Meta calls it the customer service window. Its purpose is to let businesses help customers who reached out, while stopping unsolicited free-form messages to people who did not.
The clock is per customer and per business number. If Achieng writes at 10:00 on Monday, the window runs until 10:00 on Tuesday. If she writes again at 18:00 on Monday, it now runs until 18:00 on Tuesday.
What can you send inside the window?
Anything WhatsApp supports for business: plain text, photos, videos, documents such as a PDF quote or invoice, voice notes, locations, contact cards, reactions, and interactive messages with buttons or lists. You can also send templates inside the window.
That flexibility is why most customer service happens here. An agent can send product photos, a price list, a Google Maps pin to your Westlands branch and M-Pesa payment details in one conversation without any approval step.
What happens when the window closes?
Once 24 hours pass without a new message from the customer, you can no longer send free-form messages. Any attempt fails. To reach the customer again you must send an approved template: utility for updates, marketing for promotions or authentication for codes.
If the customer replies to the template, a new window opens and you are back to free-form conversation.
| Inside the 24-hour window | Outside the window | |
|---|---|---|
| Free-form text and media | Allowed | Not allowed |
| Buttons and list menus | Allowed | Only as part of a template |
| Templates | Allowed | Required |
| Who can start it | The customer, by messaging you | The business, with a template |
| Typical use | Answering questions, quotes, orders, support | Reminders, order updates, offers, follow-ups |
| Cost on chat.or.ke | KES 0.75 per reply | KES 0.90 per update, KES 4.50 per promotion |
How does the window affect what you pay?
Messages your customers send are free. What you send is charged by type, and replies inside the window are the cheaper category, while templates sent to restart a conversation cost more, with marketing the highest.
Meta's own rules here changed in October 2026, when it resumed charging for service replies beyond a monthly free allowance per business number and began charging for utility templates sent inside an open window. The current detail is on Meta's pricing page. On chat.or.ke, a reply in the window costs KES 0.75 and Meta's fees are included in that rate.
The practical lesson is the same either way: deal with everything while the customer is still talking to you.
Worked example: a Nairobi furniture shop
A customer messages a furniture shop in Industrial Area at 21:40 on Friday asking whether a three-seater sofa comes in grey. Nobody is on duty.
- What goes wrong: an agent sees the message on Monday morning, more than 24 hours later. The free-form reply fails. The shop must send a template, and a generic "Thanks for your enquiry" marketing template costs more and feels cold.
- What goes right: the shop's AI assistant answers at 21:41 with the grey option, photos and the price, then asks whether the customer wants delivery. The customer replies on Saturday morning, which restarts the window, and an agent on the Saturday shift confirms delivery to Ruaka and sends M-Pesa details. Everything happens inside the window as replies.
The second version is cheaper, faster and more likely to end in a sale.
How do you keep conversations inside the window?
Answer quickly and completely, and use automation for the hours your team is away.
- Reply fast. Our guide on reducing first response time covers staffing and routing.
- Use the AI assistant out of hours. chat.or.ke's AI assistant answers common questions from your own knowledge base in English and Kiswahili, and hands over to a person when needed.
- Ask a question back. Ending a reply with a simple question such as "Which colour would you like?" invites the customer to respond, which keeps the window open naturally.
- Use buttons. Interactive menus make it easy for customers to reply with one tap.
- Watch the timer. chat.or.ke tracks the window for every chat and tells agents when a template is required.
Do not try to game the window by asking customers to send a message every day; it annoys people and does not build trust.
Does the window apply to Facebook Messenger and Instagram?
A similar rule applies. Messenger and Instagram allow businesses to reply within 24 hours of the customer's last message, and a person on your team can reply for up to 7 days. chat.or.ke shows the time left on every chat, whichever channel it came from.
Click-to-WhatsApp ads add one more wrinkle. When a customer messages you from one of those ads and you reply within 24 hours, Meta opens a free entry point period that lasts longer than the normal window. Read Click-to-WhatsApp ads and the free entry point explained for the detail.
What should you do after the window closes?
Pick the right template for the purpose. A reminder about an existing order or appointment is utility. Anything that promotes, re-engages or invites is marketing and needs the customer's opt-in. Our guide on getting WhatsApp templates approved shows how to write both, and WhatsApp template categories explained covers the categories in depth.
Published 20 October 2026 Updated 20 October 2026 Plain-text version
