Regulation 16

All vouchers must contain such particulars as are necessary to enable those vouchers to be checked.

When supplies are furnished or any work is carried out under an agreement or a contract, there must be attached to or shown on the voucher relating to the agreement or contract a certificate stating that the payments for those supplies or that work are made in accordance with the terms of the contract or agreement and, where supplies are furnished, that those supplies have been received or, where work is carried out, that the work has been properly done.

Where a payment for work is made on an account, no more is to be paid than the cost of the work certified to have been carried out.

If a deduction in respect of a penalty or damages is made from the amount payable under a contract, only the net sum is to be paid.