What happens to the one time Office purchase if I buy a new computer?

Hi,

If you purchased a new computer and own the Office Personal, Home and Pro package, you can install it on that computer (whether it runs Windows or Mac).

There is no issue, provided you have the account associated with the Office package; however, you can only use it on one device at a time—you cannot use it simultaneously on both.

Please consider rating the question (accepting the answer or not) and visiting the Microsoft Q&A community if you have further questions.

Thanks.