Ted from Cameron writes:
If Microsoft XP and Microsoft Office 2003 is past support life, does that mean I can use the same license on numerous computers now?
Sorry Ted, it does not. Nothing has changed about the license to the product. It will still function on your computer, but Microsoft is no longer providing security support. And even if you could, it really wouldn’t be a great idea to put programs with no security support on multiple computers. Unless you were planning to keep all of those computers offline permanently.
There are several office options out there for you for office programs on multiple computers. An Office 365 Home subscription  will give you 5 licenses for office products for $99 a year. You can use Microsoft Office Apps for free  online or you could try LibreOffice  for free. These are all much better choices than using an unsupported program.
You can also check out this article that outlines XP upgrade options.