A family of Microsoft word processing software products for creating web, email, and print documents.
Hello @Peter Muldoon
I understand the frustration, especially since Word was working previously and you purchased the subscription through Apple.
Because you purchased Microsoft 365 through the Apple App Store, Apple manages the subscription billing, but Word still needs to link that purchase to the Microsoft account used in the app. Microsoft specifically provides a Restore Previous Purchase option for Microsoft 365 subscriptions purchased through Apple.
Microsoft - Restore a previous purchase for Office for Mac
In Word on your Mac, sign out of the Microsoft account, close all Office apps, reopen Word, and sign back in to the Microsoft account originally associated with the purchase. Then look for Restore Previous Purchase and make sure you're also signed into the Mac App Store with the same Apple Account used to purchase the subscription.
You can verify the Apple subscription under System Settings → Apple Account → Media & Purchases → Subscriptions. If Microsoft 365 shows as active there but Word still gives error 1303 after restoring the purchase, the next step should be Microsoft activation support rather than purchasing another subscription.
Also, Peter, I recommend removing your telephone number from this public Q&A post for privacy. Microsoft support staff do not need your phone number posted publicly to troubleshoot the activation issue.
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