provided, that, such fee changes will only be effective as to usage of the ZeroBounce Hosted Service that occurs after the effective date of the relevant fee change. Unless otherwise stated, all fees are stated in U.S. Dollars. Customer will pay Provider in advance for use of the ZeroBounce Hosted Service, by purchasing credits, unless other terms are agreed upon by the Parties. All sales/prepayments for credits made to Zero Bounce are final and non-refundable.