The European Central Bank has published an updated booklet setting out how national compilers in the European System of Central Banks should transmit Balance of Payments and International Investment Position Manual sixth edition (BPM6) balance of payments, international investment position and international reserves data, also covering monthly reporting of euro banknote shipments. The guidance replaces the April 2024 edition and applies to transmission for the 20 euro area countries as applicable from 17 March 2025. Key changes include extending the definition of non-compliance to explicitly capture “grossly implausible data” alongside timeliness, format, completeness, validation breaches and missing qualitative metadata templates for transactions and net errors and omissions adjustments above an indicative threshold of EUR 3 billion. The booklet also adds a new section on dealing with quality reservations, discouraging the use of confidentiality flags (“C” or “N”) to suppress low-quality data in favour of observation-status flags such as estimated, provisional or low reliability, and clarifies that the ECB will inform national compilers when a non-compliance case arises and provide a justification. Supporting updates cover the transmission timetable and standards, including 14:00 CET deadlines for monthly balance of payments data by the 44th calendar day, quarterly balance of payments and international investment position data by the 82nd day, monthly reserves template data by the tenth day and monthly banknote shipment data by the 35th day, as well as adjustments to the Requirements Matrix and added comparison sheets to improve transparency versus Eurostat requirements and changes from the prior booklet. The update reorganises some requirements and series classifications, reiterating the distinction between mandatory, agreed and voluntary series and noting that changes to certain voluntary or agreed series generally do not require action unless national compilers choose to transmit them, with continued reporting of some removed series not causing file rejection.