Thank you for sharing your situation, hismile64.

I'm here to provide details on your concern regarding the compatibility of QuickBooks Desktop (QBDT) for Mac 2021 on OS Sonoma and help suggest what to do for now.

Intuit released patches for QuickBooks Desktop (QBDT) for Mac 2021 last October 2023 that should make it compatible with macOS Sonoma versions. If you have installed QuickBooks Mac 2021 R13.3 or a later release, it should work with Sonoma. However, to ensure seamless functionality, I recommend seeking advice from an IT expert regarding any potential software conflicts with your current OS setup.

Concerning an upgrade, please know that new subscriptions to QBDT Mac Plus 2024 are no longer available in the United States as of posting, except for QBDT Enterprise products. The deadline for new subscriptions was September 30, 2024. For more information, refer to this article: Can't buy QuickBooks Desktop as a new US subscriber.

Given that you only need to track income and expenses, you can consider registering your current QuickBooks Desktop for the Mac version. Here’s an article that guides you through the process: Register QuickBooks Desktop for Mac.

For future reference, I'm adding this resource for information related to managing your company information: Manage company information self-help link.

We’re here in the Community if you need further clarification about QBDT for Mac 2021 compatibility with macOS Sonoma. We'll do our best to assist. Take care.