“… a Service Charge (and an Interim Charge on account) in accordance with the provisions of 1.2 and 1.3 hereof…”
“(1) If any of the relevant costs taken into account in determining the amount of any service charge were incurred more than 18 months before a demand for payment for the service charge is served on the tenant, then (subject to subsection (2)), the tenant shall not be liable to pay so much of the service charge as reflects the costs so incurred.”