Yes. When you start a free 14 day trial, you will go through a brief installation process, which will require you enter a credit card in case you do decide to continue your account after the trial period.  Once you have set up a nation, you can pause or cancel the account at any time from within your control panel under the Settings tab > Billing > Close or pause account, or the nation owner can email us at [email protected] and we can close your account for you.  If you do decide to maintain your nation after your trial period is up, you will be billed automatically at the price plan you signed up for.