The operator or, in the absence of a formal operator, the participants of a retail payment system within the Union shall ensure that their payment system is technically interoperable with other retail payment systems within the Union through the use of standards developed by international or European standardisation bodies. In addition, they shall not adopt business rules that restrict interoperability with other retail payment systems within the Union. Payment systems designated under Directive 98/26/EC of the European Parliament and of the Council of 19 May 1998 on settlement finality in payment and securities settlement systems (
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) shall only be obliged to ensure technical interoperability with other payment systems designated under the same Directive.