The parties concluded a JBCC standard-form building contract in terms of which the respondent contractor agreed to build a resort hotel for the appellant employer. The contract appointed a principal agent with authority to issue interim and final payment certificates. Due to the employer’s non-performance, including failure to make payments and provide guarantees, the contractor validly cancelled the contract. After cancellation, the principal agent issued several interim certificates (certificates 10, 11 and 12) certifying amounts due for work executed, materials on site, and damages arising from cancellation. The employer refused to pay, and the contractor instituted action and applied for summary judgment based on the certificates.