Hi Invisible
You are correct, when you transfer over from ESA and you were in receipt of WRAG or Support to UC then you do not need to hand in a fit note.
Relevant legislation if you were getting old-style employment and support allowance (ESA)
Reg 19(1), (4)(b) and (5)(b) of the Universal Credit (Transitional Provisions) Regulations 2014, which provides that a UC claimant who was entitled to ESA immediately before claiming UC and who had been, in respect of ESA, determined to have LCW/LCWRA or is treated as having LCW/LCWRA (ie, had been placed in the ESA WRAG/support group), must be treated as having LCW/LCWRA from the outset of their UC award and the LCW/LCWRA element must be included in their UC from the outset.
Relevant legislation if you are getting new-style ESA
Regulation 28(5)(b)(i) Universal Credit Regulations 2013, provides that the normal three-month waiting period for the LCW/LCWRA element does not apply if you are entitled to new-style ESA which includes a WRAG/support component.
What to do if these rules aren't followed:
If you are in this situation and the LCW/LCWRA element has not been included from the correct date, request a mandatory reconsideration (MR) and if this is unsuccessful, appeal.
Gary
Nothing on this board constitutes legal advice - always consult a professional about specific problems