I give them 48 hours, if not posted by then, they get 21 days from the clean to pay or they are charged for late payment fee,(every other company seems to do it so I thought I would try it) suprised me how many more cheques we get within a few days, the only ones that didnt like it to much was the late payers and it seemed to sort them out as they now pay in advance. Oh an old lady got a little upset with me all i said was it is company policy there is nothing I can do about it and i know you always pay on time and gave a smile, she grumbled a litle and excepted it.