Tilly
Assuming you have a current award then reporting a Change to the DWP will result in a reassessment of your claim and a new Decision will be made which should have a start date for when you notified the DWP.
If you do not have a current award then it would be a new claim which if successful will start from the date you make the application.
In both cases, you would create a Closed Decision by the Tribunal, so any award the panel makes will be from the Effective Date of the Decision you are appealing until the Effective Date of the Change or New Decision. Importantly, the new Decision will be carried forward, not the Tribunal one.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
