OK, every year (so far) we get a nomial payrise (If im lucky it might be £80 a month). This however is always 6 months behind so when we do get it they pay a lump some in 1 month but its back dated to when it should have been from therefore the lump maybe £500. I assume this wont be subject to the 10/50/50 as it is an actual payrise that will be taken into account at review time?
Just had exactly the same issue. My IP has agreed the lump sum is dealt with as 10/50/50. Then the normal increased wage is used next month to work out extra uplift.