[Yandex Cloud documentation](../../index.md) > [Yandex Cloud Billing](../index.md) > [Step-by-step guides](index.md) > Cost optimization > Purchasing a committed volume of services (CVoS)

# Purchasing a committed volume of services (CVoS)

A committed volume of services (CVoS) is an agreement to receive a guaranteed discount for consuming a certain amount of Yandex Cloud services within 6 months or 1 year.

If you are sure that your consumption of the Yandex Cloud services is going to be stable and predictable, you can purchase a CVoS and save on your resource expenses. CVoS applies to all clouds of your billing account.

## Purchasing a committed volume of services (CVoS) {#enable}

{% list tabs group=instructions %}

- Yandex Cloud Billing interface {#billing}

  1. Go to [**Yandex Cloud Billing**](https://center.yandex.cloud/billing/accounts).
  1. Make sure your billing account consumption type is `Paid version`. For more information about upgrading to the paid version, see [Activate the paid version](activate-commercial.md).
  1. Make sure the user to manage the billing account has the `billing.accounts.editor` role or higher. To learn more about roles, see [Access management in Yandex Cloud Billing](../security/index.md).
  1. In the left-hand panel, select ![image](../../_assets/console-icons/lock.svg) **Committed volume**.
  1. Review the offers:
      1. Select a service and click the section with the new offer.
      1. Select a platform.
      1. Use the service cost calculator: set the amount of resources and compare the cost when committing to 6 months and 1 year. Select the appropriate option.
  1. Check the terms of the selected agreement. 
  1. Read the agreement. If you agree to the terms, check **By clicking "Purchase commitment", I confirm that I have read, understood, and accepted the Terms**.
  1. Click **Purchase commitment**. 

{% endlist %}

After purchasing the CVoS and starting from its start date, the discount on the use of services is applied automatically. For more information, see [Committed volume of services](../concepts/cvos.md).

{% note info %}

If you have [grants](../concepts/bonus-account.md), you can use them to cover the cost of using the committed services, including during the [CVoS](../concepts/cvos.md) validity period. In this case, the discount on the use of the reserved amount of services will be applied first, and then the grant money will be spent.

{% endnote %}