# Preview Subscription Update

```
POST 
/subscriptions/:id/preview
```

Calculate what a prorated change to a subscription would settle, without applying it.

Send the `amount`, `interval` or `intervalCount` you intend to set. The response reports the credit for unused time, the charge for the new price, and the net difference that would move. Nothing is charged, refunded or stored.

Use this to show a customer the cost of a plan change before they confirm it. Then apply the change with [Update Subscription](https://docs.monei.com/apis/rest/subscriptions-update/) and `prorate: true`.

The figures are an estimate. Applying the change recalculates them at that moment, so a preview taken much earlier can differ. The same validation runs here as on the update, so a change this endpoint rejects would also be rejected when applied.

## Request[​](#request "Enlace directo al request")

## Responses[​](#responses "Enlace directo al Responses")

* 200
* 400
* 401
* 404
* 422
* 500
* 503

The proration a subscription update would settle

The request is incorrect or could not be processed

Unauthorized error. Please check your auth credentials

The specified resource was not found

The request was well-formed but could not be processed due to semantic errors

Unexpected server error

The service is temporarily unavailable