Re the late payers....
Either put up with them or dump them.... bad payers are bad payers and 99% of the time will allways be bad payers.
Other option is to tell them that if payment isnt promptly made from now on, that you are going to have to stop cleaning their windows as you cannot afford to wait and wait and wait (or words to that effect) - the shock may go one way or another, but it seems like your at the end of your rag with them if your posting about them.
I am giving consideration to putting £5 onto the price of habitual late payers - but only if they haven't paid by 28 days (I operate a 6 weekly service). My bills ask for payment within 14 days. Nearly all domestic customers comply with this. Most of those who don't are only occasional "forgetters" so no problem there.
It's just the very few hardcore, habitual late payers who I would be targetting.
If they want a loan they should go to their bank. After all, they don't ask a banker to clean their windows. However, having said that, I've no wish to penalise anyone for being on a 2 - 3 week holiday. Nor do I wish to penalise someone who is having a tight month and intends to pay me on their next monthly pay cheque - hence the 28 days.
The very worst two examples of late paying are as follows:-
Customer 1 is a £22 job. Some time ago, she asked to go 12 weekly due to money issues. I agreed as the job is linked to a couple of others (this was before I started charging more for lower frequency). Although I am occasionally paid more promptly, the typical scenario is that the first clean remains unpaid. Also, the second clean remains unpaid until a week or two before the third one is due when she makes a BACS payment to my account for both cleans. Effectively, this means that I wait for the payment for the first clean anything up to 23 weeks (and up to 11 weeks for the second). Due to local issues and a commercial job nearby, this is done on a rigid 12 weekly cycle.
Customer 2 is a £14 job. It is 6 weekly (meaning 6 - 8 weeks unless in a harsh winter). The typical scenario is that I receive a cheque for 3 cleans a week or two before the fourth clean is due. They have been given my BACS details and were going to pay by transfer so I don't know what happened there. If the payment time spans a harsh winter, it is quite possible for me to be waiting as long as 6 or 7 months for payment for the initial clean.
As I say, these are my two very worst examples. Other regular late payers don't keep me waiting as long or do tend to pay for two cleans shortly after the second one has taken place. Example 1 seems worse because payment is made shortly before the third clean and because of the long interval between cleans.
It's fair to say that if all, or even many, of my customers paid in the manner as in the two examples, I could experience severe financial difficulties.
I wouldn't want anyone to actually pay me the extra fiver. I would far rather them pay within the 28 days.