How to enable auto archiving
Archiving orders can make searching in the sales list quicker. Archiving simply flags a sale as archived and does not remove any sales or data. Orders that have been fully shipped and are older than the archive period will be marked as archived on a daily basis.
1. Click "Settings"
2. Click "Misc Settings"
3. Select how soon you would like to archive orders (in months).
4. Click the "Save" button next to the option