To the extent permitted by State law, the council shall audit and allow all accounts chargeable against the City, but no account or claim or contract shall be received for audit or allowance unless it be accompanied with the certificate of an officer of the corporation or an affidavit of the person rendering it, to the effect that he verily believes that the services therein charged have been actually performed; or the property or goods have been delivered to the city; that the sums charged are reasonable and just; and that to the best of his knowledge and belief no actual set off exists nor payment has been made on account thereof except such as are endorsed or referred to in such account or claim. Every such account shall exhibit in detail all the items making up the amount claimed and the true date of each.