Of course, any time You can switch to another tariff plan to a higher or lower. For plan change, You need to double click on the desired service in the field "Tariff plan", select the desired, click on the button "Ok". Allocation of funds paid tariff plan automatically.
Tariff plan can be changed no more than 1 time per day.
If you want to test a website before changing the DNS, or you just changed DNS, and while waiting for their updates, but now you need to start working on a website, then we can suggest you a solution in this situation.