Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hi P Thayer,
Based on your current situation, I recommend subscribing to Microsoft 365 Personal. This is a subscription-based product that you can pay for annually or monthly and can cancel at any time. It supports use on up to five devices. Once you have the subscription, you can directly download Office for Mac version 16.77 on your current Mac. This way, even if you switch devices in the future, you can continue to install and use the latest version of Office without having to repurchase it.
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For Office 2021, this is a permanent license that can only be used on one device and is now three years old. Although it would also work on your current MacOS, I don't think it's the best fit for your specific needs.
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Best Regards,
Jonathan Z - MSFT | Microsoft Community Support Specialist