327. Interim certificates.

The purpose of interim certificates is to provide for payments on account, for example by reference to the value of the works or by stage payments of fixed or variable sums1. Most contracts expressly provide that sums paid on interim certificates will be subject to adjustment on the issuing of the final certificate but interim payments have always been regarded as subject to such adjustment2. An interim certificate will not be taken as an approval of the work3. In general, an interim certificate creates a debt in favour of the contractor which the employer must pay at once4 subject