Not sure this is quite what I'm looking for but I could be weel wrong.

I need to tell Excel that unless all three cells meet a certain
criteria, then the validation must fail. The problem is that the
single entries for each cell will be different but mean the same thing.

A1 = East Midlands Housing
A3 = Allocations EMHA
A5 = Arrears EMHA

In this case, the validation would pass because all the entries relate
to the same company. I need to build this into an array (somehow) and
compare the cell values with that array?