I am moving to a new iMac whose OS will not support 32 bit apps. The last 32 bit app I have is Quicken so I thought I'd get the 64 bit version to use on the newer Mac but 'It ain't gonna happen'. The new version of Quicken simply refuses to input the data from the old Quicken. I spent considerable time with a Quicken support person who tried various things but, in the end, he said: "It's not going to work. You'll be starting from scratch".

So I figured, if I'm starting over I might as well try an Excel database because my needs are simple. I just track credit cards. The problem is getting the data into Excel.

Thus far I have created QIF files for every one of the accounts in the old Quicken but am stymied at getting the QIF files converted to Excel. The Quicken is old enough that it doesn't have export options other than QIF.

A problem with QIF is it keeps changing. You might take a look at MoneyDance 2022. I have had good luck importing data from multiple different accounting apps, and just reverted back to it after a couple of years with the new Quicken (which is now a completely separate company from Quickbooks.) I reverted because MonayDance has adopted a new global standard for downloading bank data that is IMHO far superior to the one used by the current version of Quicken. MoneyDance 2022 imported all of my data from Quicken without a hitch.

Try opening the QIF files in Apple's Numbers, via File>Open. What happens when you double-click on the QIF file? Does it want to open in Quicken?

I second the the choice of MoneyDance. It is very stable, mimics a lot of Quicken "style". Check out QIF Importing with MoneyDance. In the sidebar on that same page are links to possible problems and importing for a Mac from other versions of Quicken.

This generate a dialogue box that says it can't be opened because the File Format is invalid.

Not much. It opens with a window that has a pile of arcane information all down the left side.

As far as I know, all versions of Quicken can export its data in a CSV (Comma Separated Value). Pages, Excel, almost any spreadsheet application, and moneydance along with most accounting apps can open and read CSV format tables. But a word of advice, when converting to other apps using CSV, setup your accounts in the new system first then import the data using the CSV, or QIF option. I do not know of any spreadsheet that can read a QIF file.

That's correct and the old Quicken did offer CSV but each was specifically for something or other, none of which was Excel. However, it's now moot as the old Quicken won't work with Big Sur. Since I'm back to the starting line and facing a learning curve, whatever I do, I'm now considering the creation of a database in Excel.

That is strange. Like joemikeb said, CSV is a generic standard that any spreadsheet software can import. It might be worth a try to export into a CSV format and see what you get when you import into Excel. It should be a very quick process, export/import.

You will likely have choices to make before a CSV can be accurately imported, but the basic principles are dead simple. In my case when importing to MoneyDance 2022 from Quicken 6 I had to tell the import utility to ignore some columns.