> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thinnest.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Windows and what gets charged

> The 24-hour window, the 72-hour free entry point, and why answering costs far less than starting.

WhatsApp charges **per message**. Every template you send is its own charge, at
a rate that depends on the recipient's country and the kind of message.

The 24-hour window is a separate thing, and the two are easy to confuse: the
window decides **what you are allowed to send**, not how a charge is counted.

## The 24-hour customer service window

When a customer messages you, a 24-hour window opens.

**Inside it**, the agent replies freely, in its own words, as many times as the
conversation needs. Cards, buttons, images — anything.

**Outside it**, nothing but an [approved template](/meta/template-review)
reaches that customer. Not a short message, not a follow-up question. Nothing.

<Note>
  Every customer message **resets** the window to a fresh 24 hours. A
  conversation that goes back and forth over three days never leaves the window.
</Note>

## What gets charged

| Category           | When you use it                            | Cost                                                                                  |
| ------------------ | ------------------------------------------ | ------------------------------------------------------------------------------------- |
| **Marketing**      | Offers, launches, re-engagement            | The most expensive by a wide margin                                                   |
| **Utility**        | Order updates, reminders, receipts         | Far cheaper than marketing — and **free inside an open window**, until 1 October 2026 |
| **Authentication** | One-time passcodes                         | Priced separately per country, in or out of the window                                |
| **Service**        | The agent's own replies, inside the window | Free until 1 October 2026 — see below                                                 |

Messages your customers send you are never charged.

<Tip>
  **An open window makes two things free, not one.** Until 1 October 2026 it
  covers the agent's own replies *and* any utility template you send while the
  window is open. So an order update sent to somebody who is mid-conversation
  with you costs nothing, where the same template sent a day later is charged.

  Authentication is the exception: a one-time passcode is charged whether or not
  a window is open.
</Tip>

<Tip>
  **This is why answering is cheap and starting is expensive.** An agent handling
  forty inbound questions costs a fraction of forty marketing sends. Support
  automation pays for itself long before outbound does.
</Tip>

Rates vary by country and change from time to time — India differs from the US
by a large multiple. Your [usage page](/workspace/usage) itemises what you were
actually charged, by category and country.

## In-window messages become chargeable on 1 October 2026

<Warning>
  **This one is worth planning for.** Two things that are free today stop being
  free on **1 October 2026**:

  * **The agent's own free-form replies** inside the 24-hour window, which is
    most of what it sends.
  * **Utility templates** sent while a window is open.

  Both are then charged at the ordinary utility rate for that country. A
  WhatsApp conversation gets more expensive on that date, and if you run
  pay-as-you-go your balance will drain faster than it does now.
</Warning>

You will not have to remember this. A notice appears on your
[usage page](/workspace/usage) in the run-up, and you get a notification before
the date — so the first you hear of it is not a smaller balance than you
expected.

Nothing about how the agent works changes, and nothing you have built needs
rebuilding. What changes is the arithmetic: today a long back-and-forth costs
almost nothing, and after that date each of the agent's replies carries a
charge.

## The free entry point

<Card title="72 hours free" icon="gift">
  When a customer arrives from a **click-to-WhatsApp ad** or a Facebook page
  call-to-action, and you reply within 24 hours, nothing in that conversation is
  charged — **for 72 hours**. Marketing templates included.
</Card>

Three times the normal window, at no cost, and it covers the most expensive
category on the rate card. If you run WhatsApp ads at all, this changes the
economics of answering quickly: a reply inside 24 hours turns a paid
conversation into a free one.

Free entry point conversations show in your usage.

## What this means in practice

<AccordionGroup>
  <Accordion title="Answer fast, especially from ads">
    A reply within 24 hours of a click-to-WhatsApp ad buys 72 free hours. A reply
    on day two buys nothing.
  </Accordion>

  <Accordion title="Batch your outbound">
    Every template is charged. Two separate utility messages an hour apart cost
    twice what one message covering both would.
  </Accordion>

  <Accordion title="Send the utility template while the window is open">
    Until October 2026 an order update, a reminder or a receipt costs nothing if
    the customer is still inside their 24-hour window, and the ordinary rate the
    moment it closes. The same message, the same template, two different prices
    — so timing it with the conversation is worth real money on any volume.
  </Accordion>

  <Accordion title="Do not reach for a template when free-form will do">
    Inside the window the agent can simply answer, in its own words, for nothing.
    Check the inbox before sending a template to somebody you are already talking
    to.
  </Accordion>

  <Accordion title="Prefer utility where it is honestly utility">
    Far cheaper than marketing, and it reaches customers who opted out of
    marketing. Only where it genuinely is utility — see
    [the categories](/meta/template-review#choosing-the-right-category).
  </Accordion>
</AccordionGroup>

## What you cannot do, at any price

<Warning>
  * **Send free-form text outside the window.** No amount of paying unlocks this.
  * **Send marketing to somebody who opted out.** Refused, and correctly.
  * **Open a window by sending yourself a message.** The window is opened by the
    customer, or by a template you pay for.
</Warning>