Conversion to quickbooks Mac from windows

Good day, PaulArthur.

We're unable to open company or backup files from on older QuickBooks to a newer version. 

You'll want to get the latest version of QuickBooks for Mac so you can open your file in Mac. You can get the upgrade from this link: https://quickbooks.intuit.com/desktop/mac/.

After getting the upgrade, follow the steps in article to move your data from Windows to Mac: Convert a QuickBooks for Windows file to QuickBooks for Mac.

I'll be around if you need anything else. 

Thank you for the response and details. Just one last question. 
It is my understanding that you can only upgrade for example 2018 to 2020. Is this true of windows to Mac as well or do I need to convert 2020 windows version to 2020 Mac? 

@PaulArthur 

Some downgrades are possible depending on the transactions used. I know the vendor who can provide such service. But for most of case, it is better purchasing the latest QB version. Open your QBW file of 2018 on trial license of Pro 2020. Then convert the data file to Mac version and open it on trial license of Mac 2020. Once you are ready to proceed, purchase a new license for Mac 2020.