Can I Combine PST Files from Different Outlook Versions?

Yes, you can combine PST files created by different versions of Microsoft Outlook. Outlook uses two PST formats: ANSI PST (used by older Outlook versions such as 2002 and earlier) and Unicode PST (used by Outlook 2003 and later). While they have different storage limits and internal structures, they can still be merged into a single Unicode PST.

If you're using Outlook manually, the process can be time-consuming because you need to open each PST file separately and copy or import the data into a new PST. For users with multiple archive files, this quickly becomes repetitive.

A simpler approach is to use a tool like Advik PST Merge Tool , which can merge both ANSI and Unicode PST files into a single Unicode PST while preserving the original folder hierarchy, emails, attachments, contacts, and other mailbox items. This is especially helpful when consolidating old Outlook archives before migrating or creating a single backup.