(14)Technical standardisation is a cornerstone for the integration of networks, such as the Union payments market. The use of standards developed by international or European standardisation bodies should be mandatory as from a given date for all relevant transactions. In the payment context, such mandatory standards are IBAN, BIC, and the financial services messaging standard ‘ISO 20022 XML’. The use of those standards by all PSPs is therefore a requirement for full interoperability throughout the Union. In particular, the mandatory use of IBAN and BIC where necessary should be promoted through comprehensive communication and facilitating measures in Member States in order to allow a smooth and easy transition to Union-wide credit transfers and direct debits, in particular for consumers. PSPs should be able to agree, bilaterally or multilaterally, on the expansion of the basic Latin character set to support regional variations of SEPA standard messages.