It boils down to how much time you want to spend doing credit control.
Unfortunatley you will realise the busier you get, the more messers and slow payers you get and the more time you need on credit control.
You will also nitice that the more work you get through, the higher percentage of outstanding accs you will have at any one time. If you want to aim for the stars, and make big money you really have to swallow your pride and have a good credit control strategy in place. Its difficult not to vent your frustration on sloe paying customers, but you have to remind yourself that they are busy, like you are busy. Life is hectic and paying the window cleaner is not something they think off all day, its things like getting the food shopping, paying the council tax bill or having that fault fixed with the car.
You have to be persistant, but polite. Its a hard balance and requires skill in itself. This is why some people do credit control as a job as some just don't have the skills needed to do it.
My rules are simple, outstanding bill? no clean until cleared. I had a guy a few years back I had to chase, I couldn't get hold of him. So I stopped the clean. A few months go by and he called me up asking why I handnt been, I said hang on a moment sir ill have a look why....oh you have an outstanding bill from 4 months back, we triad to contact you about it but was unsuccessful, would you like to settle this now sir? he did, and paid for the next one in advance. Still got him to this day, and he has been worth his weight in gold as the amount of recommendations he has put my way must be in the 20's now.
so be consistant, but polite. don't take any messers, but stay professional if you can. its well worth it and you separate yourself from the other window cleaners who make it look like they are scratching a living..