"To end your account with DreamHost, you just go to the Billing > Manage Account (https://panel.dreamhost.com/?tree=billing.accounts) area of our panel, and click the "close account" link (at the bottom of the first box on that page)!
Simply follow the steps from there, it should all be very clear. If you're within our 97-day money-back guarantee period and paid with a credit card, you will even be automatically refunded the proper amount. Please keep in mind that any domain registration fees cannot be refunded, and if you had a free domain registration with your hosting it will become for pay.
Also note, only the main Web ID for an account can close it (if you've been given panel permissions to another account, you may not close it), and you must enter your Web ID password to verify your identity when closing. You can also only close your account effective immediately, so if you'd like to close your account in the future, please just return to that page on the day you'd like to! If you pay by check or money order, we cannot refund your money under any circumstance once it has cleared.
We're sorry to see you go.. hopefully you'll consider us again in the future!"
(From the Wiki. Relevant parts are bold.)
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