Client not paying on time

Hi Coaches. I have had a client for the past 6 months, and she is always late with a payment. In the coaching agreement, it clearly states that she needs to pay for the coaching in the beginning of the month, before our coaching.

On my part, I didn’t realize that my invoice service was invoicing her late, and it seems that I have gotten into a bad habit of me invoicing her late. I have fixed this, but now she seems to be in the mindset that she can just pay whenever.

I have coached her this month and she was meant to pay me at the beginning, but now it’s month-end and she still hasn’t paid. I have been following up with her and she keeps saying it will be done by the end of the day, but then alas no payment has been made ( This has now been going on for 2 weeks). For the last two days, she has been ghosting me. I know that she will pay because we been working together for 6 months and she always does, but I just feel like I need to clean things up. I don’t want to be waiting on payments and coaching people who have not paid upfront for the month, and have to sit here and police her to pay and have anxiety over her possibly not paying for coaching that has already been given. On my part, I know I didn’t show up for myself by being careless with the invoicing. It’s now already time for her to pay for the next month of coaching, but she hasn’t even paid for the previous month and I’m having mind drama about sending her a double invoice.

My thoughts are ”she is going to think that coaching is adding up and getting to expensive”
“I messed up with the invoicing and got her into this bad habit”
“I’m too relaxed when it comes to paying, and that’s why she is relaxed”

Please help coach me on this!