I had this customer for 2 years. Good paying, easy work, but the guy never payed on time. I always just let it go because it was a good job and he eventually did pay. But this last time, after two months I got tired of it. I told him very nicely that I havent received payment and I couldnt cut until i did. Finally one month later I received payment, and on the invoice he wrote" I think I'll do this from now on, thanks for a great job. Now, even though payment was always late what do you think I should do. Call him, send a letter, wait till the end of the year, or just let him go.