Colorado Revised Statutes Title 6. Consumer and Commercial Affairs § 6-6-103. Collections prohibited--penalty--definition

(2)(a) The sender of a magazine or other periodical shall cancel a subscription if any invoice is returned by the recipient marked “cancel”. Cancellation shall also occur when the recipient gives written notice of cancellation to the sender at the sender's address or at the address of the subscription department printed in the periodical, or, if no such department is listed, at the general business address of the periodical.

(b) Notice of cancellation may be given by regular mail, and is effective on the date received by the sender. Notice of cancellation need not take any particular form and is sufficient if it indicates by any form of written expression that the recipient wishes to terminate the subscription. Within sixty days after notice of cancellation for prepaid subscriptions, the sender shall refund to the recipient any amount paid for the subscription less the amount owed by the recipient for any periodicals, together with the postage thereon, if postage has been charged separately, received before the effective date of the notice of cancellation.

(c) For purposes of this subsection (2), “sender” means the publisher of a periodical, any person acting as the agent of such publisher, and any person purporting to act as the agent of such publisher, and a seller of the periodical.