If you are using the SFTP protocol, for large files (by default files above 100 KB), WinSCP uses a transfer via temporary name. So it needs create permission.

You can turn this feature off using -resumesupport=off switch.

See https://winscp.net/eng/docs/resume

I'm having difficulty with automating a file transfer with WINSCP. We recently changed vendors for a particular function, so our destination file server has changed. After modifying the destination configuration on the scripts, we began receiving a permissions error indicating that our credentials do not provide us with the "Create" permission. After contacting the vendor, they advised that they do not allow us to "Create" files but only transmit/send an already created file. Is there any particular reason that the "Put" command would result in a file creation rather than an upload/transfer? Maybe I'm looking at this all wrong though. Thanks for your review!