Yes and it's easy to do.
Since your account name also serves as your Dropbox name for customers we recommend you settle into a name the best represents your company and stick with it so your customers always have a consistent URL to upload files to you.
To change your Account/Dropbox name:
Goto: File Manager->Profile/Passsword->Change Your Account Name
Simply enter the name of the new Account Name you want and, if available, when you press the 'update' button. Your old Account Name will be invalid and your new name in place. We recommend you sign-out and sign back in using the new account name.
For instance, if you choose ‘bigsigns’ as your Account Name:
People would send files to your PixtaSynapse Dropbox: https://files.pixta.com/bigsigns
If you change your Account Name to: 'giantsigns'
People will then send you files to: https://files.pixta.com/giantsigns