While visiting a client to deliver their 2019 tax documents, one of the owners approaches you and states: "The IRS says my travel is no longer business travel, but instead, is commuting. They are saying I am going to owe taxes on the money the company has reimbursed for my travel. I spend $1,500 per week traveling, and travel at least 50 weeks out of the year, traveling weekly to Houston on Monday, Los Angeles on Tuesday, Seattle on Wednesday, Chicago on Thursday, and Philadelphia on Friday. I leave my home in Atlanta early Monday morning, and on Friday night, I fly back to Atlanta, and my home. I visit different clients each time I visit the cities to which I travel. My job is to help them get their restaurants up and running, and I am usually there from start to finish, which takes anywhere from 3 to 9 months. I have been traveling like this for the past 10 years. That is a lot of money we are talking about. The IRS also said something about fraud, fines and penalties, maybe even jail time. Are they right? Can they send me to jail for doing my job? What should I do?"

Commuting refers to travelling from your home to your workplace. It generally refers to the distance that people generally travel to get to their office or any type of workplace.

While business travel refers to not only leaving your house to go to work, but actually going somewhere else to perform your regular business activities, e.g. going form one state to another to close a sale. In order for business travel to be effectively recognized as such, it must be necessary for your business activity and it should last more than one ordinary workday.

In this case, your client continuously leaves his house and goes form one state to another performing his normal business activities. This perfectly fits the IRS's definition of business travel.

Initially, you can try to solve this issue with IRS Office of Appeals (since you are right), but if that doesn't work, then you can go to Tax Court.