When you over scan an item in a order it will be highlighted on screen with an error message

 

 

That means you have scanned more items than are required for a particular order line in the order you are scanning.

The line will also be highlighted in red to indicate there is an error. Note how 2 items are required but 3 have been scanned

 

 

To correct an over scan you have two options

 

Undo your last action

 

To undo your last action tap the menu option in the top left

 

 

Then select 'Undo Last Scan'

 

 

The over scanned line will that have the last scan removed from it

 

 

Clear Order Line

 

If you wish to scan the order line again just long press on the order line and the Edit Line box will appear

 

 

Tapping 'Clear' will clear the lines count so it can be scanned again