SliQ Invoicing automatically makes a backup of your current data the first time you close the package each day. If you mistakenly delete an item you can rollback your data to the backup saved the last time you ran SliQ Invoicing.
SliQ Invoicing Plus stores backups in:
My Documents\SliQInvoicing4\AutoBackup - for version 4 of SliQ Invoicing Plus
My Documents\SliQInvoicingLite\AutoBackup - for SliQ Invoicing Lite
For more information on creating and restoring backups see: http://www.sliqtools.co.uk/onlinehelp/creating_a_backup.htm