Hi Fredrik, 

Welcome to Box Community and glad to assist! 

In order to terminate your account, you can go ahead and cancel your subscription. 

Canceling a Business or Enterprise Account

Only the account administrator can cancel a Business or Enterprise account.

1. Go to Admin Console > Account & Billing.
2. In the Status field in the Account Information section, click Cancel Account.

   Note

   If you do not see this option, email cancel@box.com.

3. Complete the survey and click Cancel My Account.
4. Click Permanently Cancel My Account to confirm and complete the process.

The account will cancel at the end of the service term.