You can make direct debits from clients in all SEPA countries. These are the countries of the European Union, plus some others.
Please note that you must accept direct debits from all IBANs. You can’t refuse a mandate or a direct debit because the IBAN is from another country. Your systems must be able to process direct debits with IBANs from all SEPA countries.
SEPA direct debits are always in euros. Some SEPA countries have a currency other than the euro. Banks in those countries may only be able to process SEPA direct debits from a euro account and not from an account in the local currency. This may vary from one bank to another.