What’s the status of this? If you have just assigned it to the mobile user and they haven’t started work, you can cancel the assignment from the screen called “Transferred Tasks/Work Assignments”. 

@anmise ,

Thanks a lot. I just tested this and I could cancel the WO.
When the WO is started by engineer, I could un-assign it from mobile using ‘Incomplete’ option. However it will create a Cost line in the Work Order. 
Is there any way to get rid of the cost line in the Work Order so that I can cancel a Work Order even if it is started in the mobile?

Best regards
GaSoGB

If it has been started, and you use clockings, it will create a cost line. You can delete clocking and thus the costs from the work task. 

You can find the clockings in “Work Task Clockings” and then use the “Delete Clocking” command.

@anmise ,

Thanks a lot.

Much appreciated.

Best regards
GaSoGB