How to Update New Outlook's Custom Dictionary

I had a user to ask about how to update Outlook's Custom Dictionary. She had noticed that many of her Classic Outlook brand terms and acronyms were missing in New Outlook.

You may not realize that New Outlook uses RoamingCustom.dic file and has its own custom dictionary. This file is stored in the cloud. Classic Outlook uses Custom.dic file and is saved on your local computer. Both dictionaries can be updated through Microsoft Word. 

In this blog post, which contains a video, I explained the differences between the two dictionaries, where they are stored, and how to build your dictionary in New Outlook. 

#traccreations4e-p25 11/24/2025