I issued my invoices at the beginning of the month as per usual. One of my Mums had a late payment charge of 14 pounds...the reason being that I charge 10 pound if not paid within a week and then 2 pound for every day thereafter. This is from last month so hte charge goes on this month. She is not happy. The situation was that I got my invoice out on the 30th Septemebr to her, she then came back to me at the beginning of the month and requested a change to hours which I accomodated. I then revised the invoice and then she asked me to change it again, which I did on the very same day, by this time it was the 7th October. I asked her to pay immediately. She didnt , I then told her by text the next day she needed to pay to avoid late payment fee, and she didnt until the 10th. She thinks its not fair because she didnt get revised invoice until 7th. I think shes taking the piss because she should have sorted out what she wanted way before then. I give them a week to make payment and I think this is fair. I have stuck to hte letter of my rules on this occasion because in August I had aterrible situation with her that led to me having to agree to be paid in arrears meaing I didnt get paid for part of August and all of September, so I thought I really had been quite geneerous enough. What can I say to her later? Is it worth me quibbling about?