From your link:
> Your supporting documents should show the amount paid and a description that shows the amount was for a business expense.
A credit card statement typically doesn’t fulfill the second half of that requirement. That doesn’t mean the card statement isn’t a valid supporting document, just that it wasn’t enough by itself.
I too read an IRS document once, that doesn’t make me an expert on accounting. However, when every single finance person has stated that the WHAT was as important and then your own link says that too, I generally would back down and admit maybe I misunderstood and/or made a mistake. YMMV.
The IRS lists out the different forms of documentation needed to support your expenses.
https://www.irs.gov/businesses/small-businesses-self-employe...
You can see right there under Expenses that credit card statements as well as cancelled checks are valid documentation for a write-off.