New services taxation: payments made and invoices issued before tax start date may be exempt if conditions met promptly. When a service is taxed for the first time, no tax is payable where an invoice was issued and payment received before the service became taxable; likewise, no tax is payable where payment was received before taxation and the invoice was issued promptly thereafter. The rule applies mutatis mutandis to a new levy, and amounts not meeting these timing conditions become subject to the new tax or levy.