You can search for multiple series keys at the same time on the ECB Data Portal with the OR operator. Include a list of your series keys separated with "OR" to return exact matches for all series keys.

For example, you can specify a number of series keys in your search.

Alternatively, you can also include wildcards (*) in the list of series keys you are looking for. Please see the following example.

To learn more about the wildcards you can use on the ECB Data Portal, please see Can I use wildcards in the search function?.