Burr v OM Property Management Ltd 
Burr v OM Property Management Ltd  EWCA CIV 479: Court Of Appeal Affirm UT’S Decision On When Costs Are Incurred Under s20b
The Court of Appeal affirmed the Upper Tribunal’s decision ( UKUT 2 (LC)) that costs are “incurred” for the purposes of s.20b when an invoice is served or payment is made. Giving the judgment of the court, the Master of the Rolls (Lord Dyson) held that “a liability must crystallise before it becomes a cost.” Costs are not “incurred” within the meaning of section 18, 19 and 20B on the mere provision of services or supplies to the landlord or management company.
Like the Upper Tribunal, the Court of Appeal did not find it necessary to decide whether costs are incurred on the presentation of an invoice (or other demand for payment) or on payment.