Is There a Size Limit for Outlook PST File?

There are two kinds of PST files – ANSI & Unicode.

Unicode PST: Unicode is the file format of PST files in newer Outlook versions (Outlook 2003, 2007). The maximum file size limit of Unicode PST is 20 GB, which is a great storage space. This limit is perfect and smooth performance and stability. Outlook 2003 and 2007 use a Unicode PST file format, which can store data that has size limit of 20 GB, which is sufficient for storing enough data information.

ANSI PST: Outlook versions before that (97 to 2002) use ANSI PST file format restricted to U.S. English (foreign-language characters need to be encoded in that format) that has a limit of 2 GB.

Both PST formats have different limits and both have different uses, which are given below:

a. Outlook 97-2002: In Outlook 97, Outlook 2000, Outlook 2002, size limit is 2 GB, which cannot be extended. So, it is recommended not to go beyond this limit.

b. Outlook 2003-2007: Outlook 2003 and Outlook 2007 have size limit 20 GB. This size limit cannot be extended as this much size is sufficient for performance and stability reasons. If your PST file goes beyond this limit, you need to move old messages to a separate archive PST file — or delete them.