Controlling caching based on Ajax header

Users of my application can have multiple business accounts. The settings address is /settings/:id/.... When switching between accounts, the REST service receives the correct ID at all times.

The service is invoked by using this.store.find('user') to retrieve all users in the account.

The API accepts a header called account which determines which accounts users to retrieve.

If I switch to the second account, the service returns only the second account's users but the first accounts users are still cached.

How can I invalidate this cache based on header?