Rear Brake binding

Anybody have any suggestions on how to limit / avoid the rear calipers from binding?

I use mine as a daily drive and it failed the MOT last week on rears binding on.
The pads are only a year old and I remember last year it also had binding on issues. It seems as though fitting new pads, re setting the piston back to fully in cures the problem, but only for 12 months or so.
Faulty caliper perhaps?

Anyone else experience regular problems with rears?

BTW - the MOT failure was only on brakes, so apart from that it was fine

The rears are always an issue come MOT time .Normally low efficiency causes the fail on mine .It is a case of re bedding the pads and winding the caliper back annually for the MOT