How do you stop Microsoft Word underlining words in red/green when a doent is opened on a clients computer?

I know that it’s easy to get rid of underlinings on your own computer, just right click, select ignore and save your doent. But I have just opened my doent on a different computer (on the newer version of word with the ribbon at the top) and Word automatically underlined many things in green, very unprofessional for a client to see. What can I do about it?