It's supposed to be free for one person to file their state return. Why is it charging me $20?

I personally believe that what they print on the box of what the product does is not very accurate.  I only found what I was looking for, on what was included or not, by making sure I looked closely at the details of the product.  I purchased the Deluxe2020, and also the Deluxe in the prior year, and it cost me to actually file the state.  

When reading the details of the Deluxe the details say...

• Includes 5 free federal e-files and one download of a TurboTax state product. State e-file sold separately

The deluxe provides the federal forms, which is the same no matter what state you live in, and it also includes the form for whatever state you say you live in.  I'm guessing each state has it's own form and it allows different deduction and filing rules. 

The deluxe allows you to to create as many unique person's  federal tax returns as you would like.  In addition, the deluxe includes free filings, aka submission of the federal form, for up to 5 people. 

*I used the deluxe for myself, but I also file for my elderly parent, and I let my adult child use it for her taxes.  All 3 of our federal returns are 'free' to file.

The deluxe copies all of our federal information into the state form, which is California.  When it comes time to file my federal and state taxes I had to pay $20 to file my state taxes as this was not included in Deluxe.  The same goes for my parent's and child's filings; their federal filing was free, but Turbotax charges $20 for each additional state filing. 

@melpigs which TurboTax product are you using? If you're using the CD/Download version, there is a fee for e-filing the state return. For more information, see: Is there a fee to e-file my state taxes in the TurboTax CD/Download software?