I'm self employed and I've done 15 hours a week for a client for the past 10 months now. I bill every 4 weeks and there's been no issue
In recent months though, the work has crept up a little bit it does ebb and flow so 15 hours more or less covers it and anything extra I tend to bill for after checking first
Now though they are often calling on me at weekends or evenings. A few months ago I suggested we go to 20 hours a week standard and was told maybe they will reconsider this in a few months time
But now I'm regularly tipping towards 20 hours or exceeding and I just need to know where I am and block these 20 definitive hours out my schedule (I do other work)
How do I word a polite but firm ish email to set these additional hours in stone? Thanks