The ability to change your Poshmark username is not yet an option (as of March 2, 2019). There is a possibility of this changing in the future, however.
For now, Poshmark asks that you contact their support team if you would like to request a username change. I am however uncertain of the success rate in doing so.
About the Author – Hey there! I am a 31 year old male residing in Edmonton, Alberta, Canada. My main source of income is through reselling clothing on Poshmark, with my second source of income being through creating and running numerous websites daily. (Shoutout Edmonton, Shoutout Sudbury, Edmonton Talks News, & Alberta Missing Report to name a few.) I also make helpful Poshmark-related YouTube videos! Thanks for checking out my helpful Poshmark website! If you happen to be interested, here’s my Poshmark Closet.