I have been hit by their sudden "Commercial use suspected" even though I only ever connect to one 86-year old friend. He and his wife have 3 Windows machines and he has just bought 2 old iMacs, and is trying to move to Mac in spite of my protestations. Hence a flurry of connections.
Teamviewer has a form to fill in to protest private use, but here it just leads to an error page. I found their forum, but all that reveals is a huge thread full of similar complaints, so it looks as though the Teamviewer free option is on the way out. They seem to be manually deleting any references to rivals on the forum and also any email addresses.
I still help a couple of commercial companies with their IT, but always in person. I used to recommend TeamViewer, but having delved into the shambles that is their web site, I now think the time has come to find an alternative that works to access Windows and Macs.
Any suggestions gratefully received.