Permitted Work

The letter from the DWP states: “We will pay Employment and Support Allowance from 9 March 2012.” Is this the date when I am transferred from Income Support? So from this date will I be subject to the ESA Permitted Work rules? I understand that I will then be able to keep much more of any earnings than if I was on Income Support. I shall be on Income Related ESA. I have never been on Permitted Work and have not asked permission to do any. I have identified a possible opportunity for one day a week. How exactly do I go about finding if this work would be allowed? Who do I ask? How long does it take? Do I have to see some kind of Jobcentre adviser about it?