Hi,
It's glad to hear that the Transcribe feature in Word useful. Unfortunately, Microsoft does not offer an option to purchase additional transcription minutes beyond the 300-minute limit per month.
Pooling minutes across multiple users in a tenant is also not supported. Each user is limited to their individual 300-minute quota.
If possible, you could create additional Microsoft 365 accounts specifically for transcription purposes. This way, you can utilize the 300-minute limit for each account.
If you have any feedback or suggestion about this behavior, you can try to give a feedback to Microsoft about your requirement:
Microsoft values your opinion. Your feedback will help us shape the future of Microsoft products and services for all our users.
Hope the information will help.
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