# Limits & errors

What the WeChat integration does not cover, the reply window and the common errors.

## Costs

Messages you send count on your plan's [message meter](https://zernio.com/pricing#message-rates), like every other channel. WeChat's own fees, such as account verification, are paid to WeChat.

## What you cannot do

- Message a customer more than 48 hours after their last message, or send more than 5 messages in that window.
- Send broadcasts or publish articles (not supported yet).
- Connect a Subscription Account or an unverified account.
- Call WeChat from IPs off the whitelist: keep Zernio's IPs on it for as long as the account is connected.

## Common errors

| Error | Cause | Fix |
|-------|-------|-----|
| `400` `wechat_ip_not_whitelisted` | Zernio's IPs are not on the API IP whitelist | Add every IP from `GET /v1/connect/wechat/ip-whitelist`. |
| No messages arrive | Server Configuration is not enabled, or the Token, EncodingAESKey or mode does not match | Paste the values from the connect response again, in Safe mode, and enable it. |
| Reply rejected | Outside the 48 hour window, or past 5 messages in it | Wait for the customer to write again. |
| Calls fail after a while | The AppSecret was reset in the Official Accounts Platform | Connect again with the new AppSecret. |

## Related

- [Connect](/platforms/wechat/connect) - IP whitelist, credentials and server configuration
- [Inbox](/platforms/wechat/inbox) - The 48 hour window