> For the complete documentation index, see [llms.txt](https://docs.channel360.co.za/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.channel360.co.za/api-usage/faq.md).

# FAQ

Short answers to common questions about the Channel360 API.

## Sending

<details>

<summary>How quickly are messages sent?</summary>

Channel360 queues messages by template category. **AUTHENTICATION** templates use the fastest lane, **MARKETING** templates use the standard lane, and **UTILITY** handling depends on your organisation settings. You do not set a lane in the request: the approved template category controls it.

</details>

<details>

<summary>Can one request send to many people?</summary>

No. Each request sends one message to one recipient. Send one request for each person, or use a web-app campaign for bulk sends.

</details>

<details>

<summary>Do I need subscribers, groups, campaigns or tags?</summary>

No. The recipient does not need to be a saved subscriber. You only need an approved template under your organisation.

</details>

<details>

<summary>Do WhatsApp rules still apply?</summary>

Yes. The recipient must have agreed to receive business messages, and the template must be approved.

</details>

## Replies

<details>

<summary>Why can't I reply to this customer?</summary>

You can only reply within 24 hours of the customer's latest message, and only after they have messaged you. Otherwise send a template notification. See [Notifications vs. replies](/api-usage/concepts/notifications-vs-replies.md).

</details>

<details>

<summary>Can I message a customer who uses a WhatsApp username?</summary>

Only by replying inside the 24-hour window their message opened. Sending a template to a username (BSUID) is not supported. See [WhatsApp usernames and BSUID](/api-usage/match-replies-to-your-records/whatsapp-usernames-and-bsuid.md).

</details>

## Webhooks

<details>

<summary>Why did I receive the same event twice?</summary>

Channel360 retries an event when your server is slow or returns an error. Each retry carries the same `X-Channel360-Delivery-Id` header, so you can ignore repeats.

</details>

<details>

<summary>How long do you keep trying my webhook?</summary>

Up to 5 attempts over about 15 minutes. Any `4xx` response except `429` stops the retries. See [Receive delivery updates](/api-usage/receive-delivery-updates.md#retries).

</details>

## General

<details>

<summary>What is the WhatsApp Business API?</summary>

It is WhatsApp's service for businesses to message customers from their own systems. Channel360 connects your organisation to it. Once your WhatsApp Business account is approved and you have an approved template, you can send messages through the Channel360 API. See [WABA Prerequisites](/whatsapp-business-api/waba-prerequisites.md).

</details>