Text expansion tools are essential for anyone who finds themselves constantly copying and pasting the same information multiple times every day. Over the years we've recommended TextExpander and aText, but neither is exactly cheap. If you're looking for a free alternative and don't mind messing with configuration files, you should check out Espanso.
This is a free and open source application for Windows, Mac, and Linux that can do pretty much everything those paid apps are capable of, for free.