ESA claim

When my ESA was calculated the DM would only deduct the mortgage payments from the income I receive from my buy to let. It meant that they classed me as having £96 a week income, which is not what i receive at all, I end up with £50 a week at the very most. They would not take into account compulsory expenses like ground rent etc. This meant that the only reason I get a little ESA is due to a disability add- on of £62.45 which enabled an ESA payment of £54.70 maximum weekly when my savings dropped to below £6000. I believe I only get the £62.45 because of my PIP and also because my son is still a dependent. When my son is no longer a dependent as in 31/8/2017 when child benefit stops, am I right in saying that I will no longer be entitled to that £62.45 disability premium. If so that mean my ESA payments will stop. Am I right in saying however if my son gets awarded PIP then even though he will in September be a non-dependent I will still get the £62.45?

Also my ESA says payable until 22/9/17 whereas i would expect it to stop when my son becomes a non-dependent at end of Aug. Is this some sort of run-on? I am trying to work out if I slow down the sale of my buy to let to try and synchronize it with completion of a shared ownership purchase whether i will still fit the in receipt of ESA payment criteria. I think I need my sons PIP claim to be sped up too.

I thought the September date was something to do with my son no longer being a dependent ( they will know he will definitely not be because he is almost 20 ) but it is more likely that they have given the Sep date as a date when they expect the buy to let sale to have been completed. The rules/leg says 26 weeks or longer for capital in property being sold to be ignored to enable esa payments. I am wondering, if they stop my esa at end Aug when my son becomes a non-dependent but then say mid september he gets awarded pip which is backdated to march, whether they will reinstate my esa from 1st Sep. If so will they count it as continuous ESA , only if i am able to do the shared ownership scheme then i have to have been on esa for 39 weeks continuous