When I was assessed by the CMS, as bad luck would have it, I'd received in the previous tax year a one-off lump sum pension payment of a few K that obviously made my payments greater than (in my view !) they should be. Anyway. I was assessed this year in October.
By the time of the new tax year, obviously my income will be back to its usual levels, plus I've increased my pension contributions from salary to 12% - not unreasonable given that I'm in my early 50s.
So - at what point can I re-apply for an assessment, as those two factors will mean a >25% change in income come April ?
I would call them immediately - I would amend your pension so you are comfortably above a 25% change so they don't think it's purely to avoid paying as much maintenance, you can always reduce it after you have been reassessed.