ESA to UC Forced Migration

Not sure if this will help but I recently went through something similar.

I needed to change my child tax credits claim but my area is a full UC area, so had to make a new claim for UC.

I also thought my claim for child tax credits would continue because it was an existing claim that was being amended. Apparently not.

I also receive contribution based ESA

I now receive contribution based ESA and UC. Fortunately, my case worker is really knowledgeable and has been helping to sort things out for me bacusse everyone else that I’ve spoken to at UC has given me wrong advice - including telling me that I would have to claim new style ESA, which isn’t the case.

If your case is like mine, I will continue to receive contribution ESA and UC.

Yes, that's my problem everyone I have spoken with has given me different advice. According to HMRC a change in circumstances does equal a new claim and from what I have read that is true.
When my wife had left me, if DWP had not given me incorrect advice, then I would of naturally contacted HMRC and informed them of the change instead as they promised I relied on DWP to pass on my change of circumstances info, now 4 months later my area has changed over and I am being to claim UC but without migration protection.
The CAB advice I have now received is forget claiming UC and wait until the new legislation is passed, protecting people on severe disablement premium then claim UC and migrate naturally. I am not sure though I can financially withstand, such a drop in money with my own health needs as well as trying to look after my son.

Unfortuntily it seems impossible to make a complain when it is 2 different departments you are dealing with (HMRC & DWP). I have made a complaint to HMRC, but theoretically, they have done nothing wrong.