Oh you'll get a lot of advice on this, don't you worry! 
I always leave a payment slip and envelope (NOT STAMPED)
I have no problems, people seem to prefer it!
Having said that only this evening quoted a customer,
got the job, do it Friday...
Told him how to pay if not in...
No cheque book... "never had one, not likely to get one!" 
I have a few customers without cheque books, these just tend to transfer via online banking or send Paypal payments.
Didn't have any trouble changing over, not collected for about 3 months now

I guess problems could come... but most customers I told about it said something along the lines of "oh it must be a terrible hassle collecting in the evenings... yes thats fine, thats more convenient for us anyway"

Hi all, i really need to make a decision and need to do it soon
at present i am collecting all my window cleaning payments 3 times a week, but its become too costly and too time consuming.
I am gonna change too customers sending in payments and paying online, but am just worried that they will not comply paying within seven days.
Has anyone else just done similar of late, and gave up collecting?.
I need to type up a flyer letting them all know, any advice on how to word it?
Any advice appreciated
This how I worded my letter:
Dear Customer,
To make my business more efficient and to make payment for your window cleaning service less intrusive, starting with your next clean, I will be changing to payment by one of the 3 following methods:-
Along with my card, I will leave an addressed envelope which you can use to send me a cheque. Please make cheques payable to ".........".
If you are online and have a PayPal account, you can send payment to
xxxxxxxx@xxxxx.com. Please make a note of your house number/name and street in the subject field.
If you would like to pay by direct transfer into my account, please give me a call and we can arrange this.
In order to maintain a consistent service, in all cases, I would be grateful if you could send payment within 7 days of the clean if possible.
As always, if you have any problems with this or any aspect of my service, feel free to let me know.
Many thanks