A bit of both, but mostly the exchange rate the bank gives you is quite poor. The banks take a fairly sizeable slice when they convert money for you - hence the reason for the popularity of dedicated exchange sites. The exchange rate you are charged isn't a fixed amount. Not only does it vary from day to day but also from provider to provider. In every case you need to shop around. For example. I took the euro figure you give above and put it through
Bank of Ireland's Foreign Exchange Converter, it gave me £9881.59 and a rate of .761 (this is not including any charges). Putting it through
CurrencyFair I come out with £10,016.77, inclusive of their fee, at a rate of 0.7716.
Transfermate quote £10,049.09 (fee excluded). https://transferwise.com/ (Transferwise) quote £10,004.27 (fee included).
As a rule of thumb - banks are not offering competitive forex for transactions in your ball park (come to them with a million and see if they give you a better rate
) Insofar as I can see once you are above €10k one of the sites I have linked above will always give you a better rate. The problem for you is you need to get set up on them first (it isn't too arduous but it does require similar documentation to setting up any bank account), transfer the amount to them in euro, then transfer from there to your target account. It is more longwinded but it will save you a couple of hundred euro every time!