The DWP site has a lot of information here. The stated aim is that no-one will be worse off in the short-term. As an existing claimant for tax credits the changes should be phased in very gradually.
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When does Universal Credit start?
April 2013 ? launch of Universal Credit pathfinder
Starting in April 2013, DWP, with our delivery partners in HMRC and local authorities, will introduce Universal Credit to claimants within certain areas of the North-West of England. This ?pathfinder? stage will help us ensure that Universal Credit is ready to go live across the rest of the country later in 2013.
Universal Credit Pathfinder ? Press Release 24 May 2012
October 2013 ? national launch of Universal Credit
New claimants: They will be able to make claims for Universal Credit from October 2013, while claims for existing benefits and credits will be gradually phased out. From April 2014, all new claims will be for Universal Credit.
Existing claimants: They will move onto Universal Credit in line with a phased approach that we expect to have completed by the end of 2017
This phased process will be completed in 2017 and we will continue to provide information on this, as it becomes available.
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