Um, that’s worded misleadingly. All EU countries that switched to the Euro had a period of several years during which you could exchange the old legal coins and bills to Euros, at banks. Originally the central banks would also sometimes take foreign EU coins. Then the first grace period ran out, and you had to go to the Central Bank, because the normal banks were no longer required to exchange old coins. They also stopped taking foreing bills/ coins.
Now - almost a decade later - some countries have stopped exchange (assuming that enough time has passed to find all the lost coins under the couch, and the hidden treasure under the mattress). Other countries, like Germany, have unlimited exchange at the Central Bank. There is also a tigher control there, because of the forgeries (pre-Euro, the DM was so stable that it was favoured as inofficial currency in many Balkan countries, which lead to about 100 Millio. DM counterfeit).
Except for the many special occasions at the Wiesn, Frühlingsfest, Auer Dult when they have Nostalgia days and the merchants accept 2 DM = 1 Euros. Many charity drives also do that, set up a big box in a shopping mall and collect DMs. It’s surprising how many people still have coins lying around…
No, last time I went to the Central Bank branch, they just exchanged cash for cash to me.
Well, no. The exchange rate DM to Euro is fixed and that’s what you will get at the Central bank. The rate Euro to US dollar is fluctuating, though, and any bank will charge you a hidden or open fee (mostly hidden) for exchanging currencies that results in a lower rate.
Plus, if you don’t come yourself to the Central bank, you have to pay a fee to the person doing the job for you.
Oh, and if you have the time, check with a coin collectors guide before turning them in - some that are rare might be worth more than their face value!
To the OP: the charities that put up collection boxes for foreign currency at the airport turn the boxes over to professionals who sort them, bag them and then exchange them (for a fee, but with the thousands of coins, it’s still worth something and better than letting the coins leave lying around). So if you happened to have a Very Large Amount of foreign coins, I would try to contact those companies for help and accepting a fee in return.