WeChat Pay Platform

API

● If the settlement currency under my merchant ID is USD, can I price my goods or services in EUR?: No. You can only price your goods or service in settlement currency or CNY.

●How do I link my Mini Program to WeChat Pay via an institution?

1. You need to register the Mini Program on the WeChat Official Accounts Platform;

2. Provide the appid of your Mini Program to the institution to bind it to your sub-merchant ID;

3. When initiating a payment request, the institution passes the appid of your Mini Program to the parameter sub_appid and the Mini Program's openid to sub_openid.

●How do I link my app to WeChat Pay via an institution?

1. You need to register the app on the WeChat Official Accounts Platform;

2. Configure the package name and signature;

3. Provide the appid of the app to the institution to bind it to your sub-merchant ID;

4. When initiating a payment request, the institution passes the appid of your app to the parameter sub_appid.

● How can I modify or delete the merchant information after I have registered a merchant ID by calling the registration API?: Modifying and deleting merchant information are not supported.

● Where can I get the API key and certificate?: You can log in to the merchant platform and set and get it in the API Security menu. The API key should be a combination of 32 characters comprised of uppercase and lowercase letters and numbers.

● Am I required to set the authorized domain name to an HTTPS domain name?: No. It can be an HTTP or HTTPS one, but you're recommended to set it to an HTTPS domain name.

● I have already passed notify_url when I place an order, but I'm unable to receive the callback. What is the reason for this?: WeChat Pay will make 10 retries in case of a callback failure. If you're unable to receive the callback even after the 10 retries, please check the network settings of the callback URL to verify whether the callback parameters can be received correctly.

● Why do I always receive a signature error when the API is called?: When a signature error is returned, please verify whether the signature algorithm is correct and whether the key used by the signature is correct.

● My fund has not been settled, but when the API for refund is called, an error message indicating my account balance is insufficient is returned. What is the reason for this?: In fact, each Merchant ID has two fund pools: the CNY fund pool and the settlement-currency one. The fund for the transactions conducted on the Day T is stored in the CNY fund pool. On the Day T+1, whether it is a holiday or a business, the above-mentioned fund is moved to the settlement-currency fund pool after being converted into the settlement currency. If the fund in the settlement-currency fund pool reaches 800 USD, WeChat will pay the fund to the institution's account on the Day T+1 (other than a holiday or weekend). Only the fund in the CNY fund pool can be used for refunds. For this reason, please ensure that the CNY fund pool has sufficient fund to cover the refunds.

● When the API for downloading statement is called, an error message indicating the statement does not exist is returned. What is the reason for this?: This is generally because the settlement feature has not been enabled, or no transaction was executed on the date you select.

● Are partial refunds supported? How many partial refunds are allowed for one order?: Yes. A maximum of 50 partial refunds are allowed for one order.

● Do I need to pass the real device IP for the Terminal IP field of payment API?: You can enter the IP of the device from which the request is initiated, or the exit IP.