Quicken 2007

Well it’s not High Sierra that needs to worried about. It’s 10.14 that may no longer support 32 bit apps. And as of a few days ago when you launch a 32 bit app while running 10.13.4 you do indeed get a warning pop-up that states your 32 bit app may have problems with future versions of macOS. I launched Quicken 2007 with 10.13.4 and got that very pop-up warning. I have been running the current version of Quicken (5.5.7 subscription version) since it came out but I just wanted to see what would happen if I launched Quicken 2007. There’s no ifs, ands, or buts about it, Quicken 2007 is likely to cease functioning sooner rather than later. It is no longer supported by Quicken either. Time to either update or stay in place going forward.

I'm running Quicken 2007 for Mac 16.2.4 (Build 25.886.1000) without a problem on High Sierra.

I follow several checking, savings and credit card accounts. I don't download data from those companies but do pay bills online with Quicken Bill Pay.

There was no difference in the performance of Quicken between Sierra and High Sierra. So if you were running on Sierra acceptably then it should perform as well on High Sierra.

I suspect you want to avoid upgrading, but in case you aren't aware Intuit sold Quicken a couple of years ago and the new ownership has released a new Mac version: https://www.quicken.com/mac

I haven't read that 32 bit apps will definitely not be supported, but I suggest that if you want to continue to use Quicken, you consider upgrading using the links FoxFifth posted. I have Quicken 2016 and there have been some changes that will take some getting use to, but I find it is still very useable.

I'm running Quicken 2007 on High Sierra with no problems.

You are welcome. As far as I know, you should have been able to import your data from Quicken 2007. Check the Help menu if you want to do that. The below is from Quicken 2016's Help.