Currency markets move
Exchange rates change as currencies are traded. The rate can move throughout the day.
An exchange rate tells you how much of one currency can be exchanged for another. The important question for a real transaction is which rate your provider uses and how that rate affects the amount you receive.
There is no single number that automatically applies to every currency transaction. Reference rates, market rates and provider transaction rates can serve different purposes.
Exchange rates change as currencies are traded. The rate can move throughout the day.
Institutions such as the ECB publish reference rates for information and comparison. These are not necessarily the rate used for a real transaction.
A bank, transfer provider or other service determines the rate applied to your transaction under its pricing model.
Even a small difference in the applied rate can change the amount received when the transfer is large enough.
Understanding the terminology makes provider comparisons much easier.
The ECB describes its euro foreign-exchange reference rates as information-purpose rates. They are useful for comparison and analysis but do not necessarily represent the rate at which an actual transaction occurs.
The mid-market rate is commonly described as the midpoint between the buy and sell rates in the currency market. Providers may use it differently in their pricing and may add other costs.
The number that matters for your transaction is the rate actually used to convert your money. Check the provider's quote rather than assuming a reference rate is the transaction rate.
A provider can incorporate part of its economics into the exchange rate rather than showing every cost as a separate transfer fee. That is why the recipient amount is often more useful than the headline fee alone.
Suppose you send an amount in your source currency. The exchange rate converts that amount into the destination currency. Any separate fee or other applicable charge then affects the total economics of the transaction.
Use the provider's final quote rather than relying on a generic currency-converter result.
Use the exchange rate together with the transfer fee and recipient amount.