Which Debit Cards are accepted in Paris and at Orly?

The Plus and Cirrus networks are universally accepted in Europe. Other minor networks are hit and miss. Some credit unions also use the STAR network that is accepted at few places in Europe. Never heard of Co-OP or NYCE. Stick with Plus (VISA) or Cirrus (MasterCard) and you will have no problems.

Last time I was in France was 2012. Both my MC and VISA debit cards worked at ATMs there then. As they both did in the Netherlands and Belgium in 2013; in Istanbul, Greece and Italy in 2014 and in the UK in 2016.

They come from 2 different credit unions. Neither charges any kind of fee. I always try to get cash from a bank ATM. I never say yes to DCC (dynamic currency conversion).

For all the scoop on money in Europe, go to the money section of this very Rick Steves website.

On my last two trips to Europe I used a Capital One and an Ally Bank debit cards, neither of them has a network symbol on them so I had no idea what networks they were part of. Both worked everywhere I tried them all over Europe.

I might suggest that you call your card providers and ask them where in Europe they are accepted. They should be able to tell you that.

Last September in Paris -- and last week in Germany -- I used my Schwab card which has a Plus logo. If you find an ATM that doesn't accept your card, there's another ATM within a block in most of Paris.

Aside from credit card issuers blocking usage because they suspect fraud (calling to report your travel plans ahead of time may help prevent this), ATM problems are pretty uncommon. I'd take both the cards with me. Carry them separately (at least one in a money belt) or keep one locked in the safe or your suitcase back at the hotel. As suggested, if one ATM doesn't work, try a second from a different bank.

Most of the card problems reported by Americans are related to attempts to use credit cards in automated terminals (gas pumps, ticket-vending machines, etc.). Sometimes that works; sometimes it doesn't. If you're prompted for a PIN, try just pressing the ENTER key; that sometimes works.

If your cards have a MasterCard or Visa logo on them, they should works anywhere in Europe as long as you inform your card issuers where you will be and when.

NYCE (New York Cash Exchange) is one of the oldest regional ATM networks that originally served only banks in the New York area.
Co-Op is a group of credit unions that, depending on the specific one you belong to, allow you to do things like make deposits at other credit union ATMs and get cash out too without fees.

Neither of these by themselves are helpful when you need to get cash in Europe.

The fact that they have the MasterCard and VISA logos on them is all you need to know. They will work.

The other networks listed are for local or regional affiliations.