This topic describes the billing information of Key Management Service (KMS), including the billing methods, billing cycles, billable items, expiration description, and renewal description.
Background information
KMS provides default keys for server-side encryption in Alibaba Cloud services free of charge. You can use the default keys without the need to purchase a KMS instance. If you want to increase the number of keys, use Secrets Manager, or build an application-layer cryptographic solution for self-managed applications, you must purchase a KMS instance of the software key management or hardware key management type. For more information about how to purchase a KMS instance, see Purchase and enable a KMS instance.
Billing overview
The actual prices on the buy page shall prevail.
Billing method: subscription.
Billing cycle: A billing cycle is the subscription duration of an instance and is based on UTC+8. A billing cycle starts from the time when a subscription instance is purchased or renewed and ends at 00:00:00 the next day after the expiration date. The start time is accurate to the second.
Billable items: You are charged by instance. The following figure shows the billable items of KMS. 
Overdue payments
KMS uses the subscription billing method. Therefore, no overdue payments can occur. You can purchase, upgrade, or renew an instance only if your account balance is sufficient.
Expiration description
To view the remaining validity period of your KMS instance, you can go to the Instances page and view Remaining Period of your KMS instance. To prevent negative impacts on your business, we recommend that you renew your instance before the expiration date.
Instance status | Description |
Before expiration | Alibaba Cloud sends you email notifications 7 days, 3 days, and 1 day before the expiration of the KMS instance. The emails serve as a reminder to renew the KMS instance. |
Within 15 calendar days after expiration | The configurations of the KMS instance are retained, including keys and secrets. However, the keys and secrets are unavailable. After you renew the KMS instance, the keys and secrets become available again. |
16 days after expiration | The KMS instance is released. Your keys and secrets are deleted and cannot be restored. Warning If you still need to use the keys and secrets in the KMS instance, we recommend that you back up the keys and secrets in advance. For more information, see Backups. |
Refunds
You can request a partial refund for KMS instances that are in the Disabled or Enabled state. You can also cancel pending renewal orders.
Before you unsubscribe from a KMS instance, we recommend that you understand the unsubscription rules, precautions, and unsubscription cases. For more information, see Rules for unsubscribing from resources.
You can unsubscribe from a KMS instance in User Center or submit a ticket to unsubscribe from a KMS instance. For more information about the unsubscription procedure, see Methods for unsubscribing resources. For more information about the refund flow after you unsubscribe from a KMS instance, see Refund flow.
Resource usage and bills
You can query and export KMS bills and bill details in User Center. For more information, see Billing details and Usage records.
Renewal description
To renew a resource in User Center, see Renewal guide for the international site (alibabacloud.com). To renew an instance in the KMS console, perform the following steps:
Log on to the KMS console. In the top navigation bar, select the required region. In the left-side navigation pane, click Instances.
Click the Software Key Management tab or the Hardware Key Management tab, find the instance that you want to renew, and then click Renew in the Actions column.
On the KMS (International) | Renew page, configure the Duration parameter, and read and select Terms of Service.
Click Buy Now to complete the payment.