No bill should ever be paid without going over the items carefully to check them up and see that nothing is charged for that was not delivered, or that nothing is charged for at a higher price than what you are paying for that line of goods When you are purchasing soil pipe for, say, 80 and 10 per cent. off the list, in making out the bills the clerks might allow only 80 per cent. discount, and that extra 10 per cent., if it represents what you are overcharged on all accounts, will amount to considerable in the course of a year. Indeed, the writer has in mind an average saving of $100 a month effected just by auditing bills and checking up such little inaccuracies as are here pointed out. When the bills have all been audited and the differences in price between those quoted and what are billed noted do not be afraid to return the bills for correction or for a memorandum of credit. Business houses like to deal with contractors who look after the details of the business, for it augurs well for their success and a long and pleasant continuation of business relations. By all means, then, audit your bills.