A session message (also called a service message) is any free-form reply a business sends on WhatsApp within 24 hours of the customer's last message. No template or approval is needed. From 1 Oct 2026, each business number gets 1,000 free service messages a month, then the utility rate.
Why it matters
The 24-hour customer-service window is the cheapest and most flexible time to talk to customers. Inside it you can:
- Reply naturally with text, images, documents, voice notes and interactive messages
- Let a chatbot answer questions, using your 1,000 free service messages a month first
- Send utility templates (charged at the utility rate from 1 Oct 2026)
After 24 hours of silence from the customer, you need an approved template to message them again.
How to use it well
- Reply fast: a shared team inbox and a chatbot help
- Encourage customers to message first: click-to-WhatsApp ads, QR codes, website buttons
- Resolve issues inside the window instead of letting chats drift
Example
A customer asks "Is size M available?" at 3 pm. The store can reply, share photos, send a payment link and confirm the order until 3 pm the next day. Those replies count toward the number's 1,000 free service messages that month.
Questions first? Chat with us on WhatsApp