In order to unsubscribe user from Centili platform you must use HTTP POST method in application/json format, sent to the following URL with parameters described below:
## POST opt-out request
## Parameters:
| Parameter | Description | Example | Required as |
| **apikey** | Centili issued service key, unique for every payment service. | f31a355df6dad07e49ba474db7ff9b07 | **mandatory** |
| **timestamp** | Unix timestamp used to differentiate every request as a unique one. The number string represents seconds. | 1462888063 | **mandatory** |
| **subscriptionid** | Unique identifier of subscription in Centili system. If subscriptionID is used than **_userid_** parameter can be skipped. | 1234567 | optional |
| **userid** | If userID is used than **_subscriptionid_** parameter can be skipped. | usrId1983 _NOTE: If the value is not set within payment request, this field will contain MSISDN of the particular customer._ | optional |
| **sign** | Signature parameter created using key issued for signing request. _NOTE: Please refer to the [signature key generation guide](🔗)._ | def0a0ba4f188cf174d383dc4d7f7041e358ba92 | optional |
## Possible server responses
| Server response | Meaning | Possible Error messages |
| **HTTP 202 Accepted** | User has been successfully unsubscribed. | / |
| **HTTP 400 Bad request** | Unsubscribe request is invalid or cannot be resolved. | -Bad request -Mandatory parameters missing! -Signature validation failed! -Subscription does not exists. -Action is not supported |
| **HTTP 406 Not Acceptable** | Opt-out transaction already exists. | There is already an outgoing opt-out process for this user. |
| **HTTP 500 Server error.** | Some unexpected internal server error has occured. | Server error. |