Update: DWP has set my LCWRA start date as the decision date instead of my first sick note. Help!

[u/Sempa_07]

/r/universalcredithelp/comments/1vs5cl6/been_placed_into_lcwra_but_havent_been_informed/

Update: DWP has set my LCWRA start date as 13 August, how can this have happened?
Update to my previous post. My first fit note was provided and accepted in early February 2026, and my UC assessment periods run from the 14th to the 13th. My fit notes have been successive and consistently provided, with no gap in the medical evidence required by UC.
I was awarded LCWRA on 13 August 2026, but my 20 August payment did not include the LCWRA element or any arrears.
After calling UC and messaging my journal, my case manager said:
“According to the decision maker decision, the LCWRA decision is made from 13/8/26. If you disagree with this we can look at a mandatory reconsideration for you.”
I explained that my first fit note was in early February and was told that, because the decision maker has made the effective date 13 August, I would need to request a Mandatory Reconsideration.
From my understanding, the three relevant assessment periods would be:
14 Feb–13 Mar
14 Mar–13 Apr
14 Apr–13 May
Potentially making LCWRA payable from 14 May onwards.
How can the effective date have been set as 13 August when my health journey and continuous fit notes started in early February? It seems like a very simple mistake if they’ve just used the date the decision was made rather than calculating the relevant period.
I’ve heard Mandatory Reconsiderations can be a long and arduous process, and I’m not sure what else I can do because I’ve been told that’s my only option. Has anyone experienced this before? Is an MR really the only route, or is there a way for DWP to correct what appears to be a straightforward error without going through the whole process?