Wont be solely Polish anyone can use it, but its like tons of foriegn banks in this country, people are used to the banks in their own country, so prefer to keep using em if they can, esp if they not great at the new language.

In Cyprus, Spain, Malta, etc etc there are "English" banks too for the same reason.

(Just thought id mention that before the PassionFord Nazi League start giving it all the ill-informed "how dare they come to our country and start their own banks, they should use ours or ideally just die" and so on like usual, as thats the way that post was sooo going )