Hi Agis
We cannot give you a definitive answer as it would depend on a number of factors such as what type of ESA are you receiving, IR or CB ESA, do you receive a SD premium?
UC is a means tested benefit which is claimed on line. It is dependant on your circumstances, you can also apply for help with rent, this is called housing element if you rent in either the private or social sector:
www.gov.uk/universal-credit.
As your review is in August you have a bit of time to prepare yourself. Check out our ESA/UC claim guide which has a section on the questions you are likely to be asked during the assessment call.
www.benefitsandwork.co.uk/help-for-claimants/esa1 If you have any further questions then please come back to the forum.
Gary
