it depends! if its a day over or two then i wouldn't charge.. or if its a one off id let it sleep.. its when it happens time and time again from same customers.
Ive text the reminder... then no payment a letter gets send as a reminder a few days later 10 days or so telling them there payments overdue and the charge of 2.50 .. most pay it as they understand..some wont.. and i don't go back
.. i have had a some say they where on holiday (probably porkies) so i let that slip and don't charge them the late fee, i don't mind them being on holiday its just the people who do it on purpose and jus let it sit there unpaid that rattle me!
You must state on your sheet after cleaning that they will be charged for late payment over your terms! most abide by it or as soon as you sent a text reminder that usually sort them out.
I find it works very well current debt i have at the moment is 220 quid and some of that is commercial 30 days payment anyway.