Regulation 61

When supplies are furnished or when work is done under an agreement, there shall be a certification on the voucher that the payments are in accordance with the terms of the agreement, and that, as regards supplies not for immediate use, the articles have been received and duly recorded in the proper inventory and, in the case of work, that it has been properly done.

In the case of a payment on account, no more shall be paid than the cost of the work certified to have been performed or the amount claimed by the contractor, whichever is the lesser.

When a deduction is made from the amount payable on a contract in respect of a penalty or fine, or other retained item, the net sum only shall be paid.