When records are deleted in Abacus Accounting, they are no longer visible to you, but still exist in the database as records marked for removal. When a database is "packed," it is rewritten to permanently remove deleted records and recover disk space. This is similar to deleting files in Windows and then having to empty the Recycle Bin.
To pack Abacus Accounting databases, select File > Utilities > Pack. The Pack Database window appears. Click Start to start the packing process.