ID requirements when opening additional bank account in Poland - bank wants a second Polish document

I opened an account with WBK a couple of years back using my UK passport, with individual zloty and sterling accounts using a single customer code (NIC) for both. It works fine. I later acquired a Polish passport by descent. Now I want to open a euro account under the same customer code, but the bank wants a second Polish document that I don't have. Is this how the Polish law works, or is it down to the individual bank's policy? I don't live in Poland, so don't have any utility bills there.

The is no strict policy. It is up to the clerk. I opened an account with WBK two years ago with my foreign passport and Polish visa sticker in it. Couple of months ago I added USD account to the same NIC, again with my foreign passport only.

It's interesting to know the policy is not rigid. It's seems if I just had my UK passport, it would have been OK, but I assumed I have to use the Polish one now.

It was one clerk consulting with another, and then making a phone call. It was near closing time on the last day of a trip, so I will try again next time. They didn't appear to have a way of dealing with a non-resident Polish passport holder with no national ID card.

Perhaps there was a misunderstanding. There are 3 ways in which you can add a new account to your NIC: 1) via online banking/BZWBK24, 2) over the phone, 3) in person. For 1) you need to have dowod osobisty entered in the system. Probably the clerk thought that you want to open EUR account yourself via BZWBK24 and that is why she/he asked for dowod.

bzwbk.pl/konta-bankowe/konta-walutowe/konto-walutowe-w-euro/konto24-walutowe-w-euro.html#tab_jak_zamowic