The "Customer" status is set automatically. You cannot write your own criteria for it. Companies with active subscriptions or orders are automatically given this status. The contact on the order gets the status as well. An order registered with a date more than a year back does not change the status.

To give all contacts at the company the same status as the company, turn on Sync status between contact and company at the top of the Journey settings page. It is off by default.

What you can define is when a company or contact should no longer count as a customer. As an administrator:

1. Go to Settings → Account → Business rules → Journey.
2. Under Lost customer, click the Lost customer row to set up the criteria.
3. Add your conditions under Criteria and click Save. Contacts and companies matching these criteria are automatically given the status. Order fields are often used, for example that the company has a lost order or has not bought anything during a specified date range.

Once the first criteria exist, add more with New criteria.